4. Gut Worms:Gut Worms: most prevalent in L&MICs (lack ofmost prevalent in L&MICs (lack of
sanitation): significant morbidity & mortalitysanitation): significant morbidity & mortality
(impair physical & mental growth, education,(impair physical & mental growth, education,
economy)economy)
– Worms (Helminths):Worms (Helminths): multicellular: usually cannotmulticellular: usually cannot
multiply in human bodymultiply in human body
– ProtozoaProtozoa are unicellular & can multiply inside our bodyare unicellular & can multiply inside our body
4 gut worms4 gut worms are soil-transmitted (geohelminths):are soil-transmitted (geohelminths): A.A.
lumbricoides, T. trichiuria (whipworm), A. duodenale, &lumbricoides, T. trichiuria (whipworm), A. duodenale, &
N. Americanicus (Hookworms)N. Americanicus (Hookworms)
6. Commonest gut protozoa:Commonest gut protozoa: G intestinalis, E histolytica,G intestinalis, E histolytica,
Cyclospora, Cryptosporidium.Cyclospora, Cryptosporidium. They causeThey cause diarrhoeadiarrhoea
• GiardiasisGiardiasis is the commonest c/of diarrhea in the West, &is the commonest c/of diarrhea in the West, &
is also v. common in L&MICsis also v. common in L&MICs
• AmebiasisAmebiasis:: 33rdrd
c/of deathc/of death from parasites in world, hasfrom parasites in world, has
the greatest impact in L&MICs. 50 million worldwide/y,the greatest impact in L&MICs. 50 million worldwide/y,
withwith 100,000 deaths/y100,000 deaths/y
• CryptosporidiosisCryptosporidiosis:: most common among AIDS & U-5most common among AIDS & U-5
Protozoa spread by fecal contamination. The cysts areProtozoa spread by fecal contamination. The cysts are
relatively resistant to Chlorinerelatively resistant to Chlorine
• Other protozoa in human gut are non-pathogenicOther protozoa in human gut are non-pathogenic
7. BangladeshBangladesh
• Worms among <2yoa:Worms among <2yoa: 80%.80%. First acquisition atFirst acquisition at
14mo14mo (1-24 mo).(1-24 mo). Common:Common: AL (commonest),AL (commonest), TT,TT,
EV, AD/NA, & mixedEV, AD/NA, & mixed
• Re-infested after 3mo of DW:Re-infested after 3mo of DW: 66%66%
• Risks:Risks: open disposal of feces, poor hand hygiene,open disposal of feces, poor hand hygiene,
bare foot, surface water for washingbare foot, surface water for washing
• Safe disposal of feces: 35% reduction, tube wellSafe disposal of feces: 35% reduction, tube well
water 48%, breastfeeding 16%water 48%, breastfeeding 16%
• Awareness & DW are crucial to preventionAwareness & DW are crucial to prevention
DW= dewormingDW= deworming
8. • The egg loadThe egg load for AL was highest among all wormsfor AL was highest among all worms
• Worldwide:Worldwide:
– AL:AL: 1.2 billion1.2 billion
– TT: 795 millionTT: 795 million
– AD/NA 740 millionAD/NA 740 million
• Disability-adjusted life years (DALYs):Disability-adjusted life years (DALYs):
– 22.1 million lost for AD/NA22.1 million lost for AD/NA
– 10.5 million for10.5 million for ALAL
– 6.4 million for6.4 million for TTTT
11. EPIDEMIOLOGYEPIDEMIOLOGY
• ALAL is the most widespread human gut nematodeis the most widespread human gut nematode
• Commonest inCommonest in tropics:tropics: poor sanitation, human fecespoor sanitation, human feces
used as fertilizerused as fertilizer
• No direct P2P transmissionNo direct P2P transmission
• IP:IP: 8w8w
• AdultAdult ALAL live in lumen oflive in lumen of small gutsmall gut. Female makes. Female makes
200,000 eggs/d to excrete in stool. Eggs must200,000 eggs/d to excrete in stool. Eggs must incubateincubate
in soil 2-3w to become infectiousin soil 2-3w to become infectious
12. Life CycleLife Cycle
• Live in small gut (1); eggsLive in small gut (1); eggs ⇒⇒ passed in feces (2)passed in feces (2)
• Unfertilized eggsUnfertilized eggs are not infectiveare not infective
• Embryonated eggs (3) are swallowed (4)Embryonated eggs (3) are swallowed (4) ⇒⇒ larvae hatchlarvae hatch
out (5)out (5) ⇒⇒ invade gut wallinvade gut wall ⇒⇒ carried to lungs (6)carried to lungs (6)
Larvae mature further there (10-14d)Larvae mature further there (10-14d) ⇒⇒ ascendascend ⇒⇒
swallowed (7)swallowed (7)
• Reaching gut they mature to adults (8)Reaching gut they mature to adults (8)
• 2-3mo are required for LC2-3mo are required for LC
• Adult worms canAdult worms can live 1-2ylive 1-2y
14. An adult AL female (genitalAn adult AL female (genital
girdle: dark circular groove):girdle: dark circular groove):
tapered ends; length 15-tapered ends; length 15-
35cm (females is larger)35cm (females is larger)
Larva hatch from egg in small gut
15.
16. CL. MANIFESTATIONSCL. MANIFESTATIONS
MostlyMostly asymptomaticasymptomatic!!
• Moderate-heavy load:Moderate-heavy load:
malnutrition, nonsp. GIT SS. Intestinal obs., more inmalnutrition, nonsp. GIT SS. Intestinal obs., more in
children (narrow lumen)children (narrow lumen)
• LarvalLarval migrationmigration:: Löffler syn., marked eosinophiliaLöffler syn., marked eosinophilia
• WormWorm migrationmigration:: peritonitis 2y to penetration, CBD obs.peritonitis 2y to penetration, CBD obs.
(biliary colic, cholangitis, pancreatitis), appendicitis.(biliary colic, cholangitis, pancreatitis), appendicitis.
Migrate more onMigrate more on stressesstresses: F, illness, anesthesia; some: F, illness, anesthesia; some
anthelmintics, O2anthelmintics, O2
SS: symptoms & signsSS: symptoms & signs
17. DIAGNOSISDIAGNOSIS
• Ova/worm in stoolOva/worm in stool
• Adult worms via rectum,Adult worms via rectum,
nose or mouthnose or mouth
L:L: fertilizedfertilized
egg,egg,
unicellular,unicellular,
requires 18d &requires 18d &
favorablefavorable
conditions toconditions to
be infective. R:be infective. R:
unfertilizedunfertilized
18. TREATMENTTREATMENT
• Pyrantel pamoate/albendazole once for aged ≥2yPyrantel pamoate/albendazole once for aged ≥2y
• Mebendazole for 3d for aged ≥2yMebendazole for 3d for aged ≥2y
• Reexamination of stool 3w later for clearanceReexamination of stool 3w later for clearance
19. Gut obstruction:Gut obstruction:
– Piperazine can worsen itPiperazine can worsen it
– Conservative suction, IVF may resolve, thenConservative suction, IVF may resolve, then
albendazole/mebendazole may be givenalbendazole/mebendazole may be given
• Surgery may be necessary to relieve gut or biliary obs. orSurgery may be necessary to relieve gut or biliary obs. or
for volvulus or peritonitis (from perforation).for volvulus or peritonitis (from perforation).
Massaging gut to eliminate obs. is preferable toMassaging gut to eliminate obs. is preferable to incisionincision
• ERCP: for extraction of worms from the biliary treeERCP: for extraction of worms from the biliary tree
20. CONTROL MEASURESCONTROL MEASURES
• Sanitary disposal of human fecesSanitary disposal of human feces
• Hand hygieneHand hygiene
• Children’s play areas need special attentionChildren’s play areas need special attention
• Vegetables cultivated using uncomposted human fecesVegetables cultivated using uncomposted human feces
must be well cooked or soaked in a diluted iodinemust be well cooked or soaked in a diluted iodine
solution. Household bleach is ineffectivesolution. Household bleach is ineffective
• Periodic deworming at schoolsPeriodic deworming at schools
21. Löeffler SyndromeLöeffler Syndrome
or Ac. Simple Pulmonary Eosinophilia.or Ac. Simple Pulmonary Eosinophilia. Rare. TypicallyRare. Typically
transient CXR infiltrates,transient CXR infiltrates, mildmild system upset,system upset,
eosinophilia. Incidence: 6/100,000eosinophilia. Incidence: 6/100,000
Pathology:Pathology: a number of allergens are linked:a number of allergens are linked:
parasites:parasites: AL, strongyloides, AL/NA, microfilaria, toxocaraAL, strongyloides, AL/NA, microfilaria, toxocara
drugs:drugs: aspirin, penicillin, sulphasaspirin, penicillin, sulphas
SS:SS: usuallyusually mild:mild: tacypnoea, rashes, SoB, wheeze,tacypnoea, rashes, SoB, wheeze, chest p., drychest p., dry
cough, F, malaise, HA, myalgia, anorexiacough, F, malaise, HA, myalgia, anorexia
22. DxDx
XR:XR: Often a fleeting transient non-segmental lung opacityOften a fleeting transient non-segmental lung opacity
(unilateral/bi-), more on periphery. No pleural E./LAP(unilateral/bi-), more on periphery. No pleural E./LAP
Eosinophilia, hyper IgEEosinophilia, hyper IgE
Rx:Rx: usuallyusually none.none. It resolves within a month (self-limited). RxIt resolves within a month (self-limited). Rx
underlying cause. In some cases steroidsunderlying cause. In some cases steroids
DD:DD: recurrent aspiration, BA, pulmonary hge., pulmonaryrecurrent aspiration, BA, pulmonary hge., pulmonary
vasculitis, cryptogenic organising pneumonia (COP)vasculitis, cryptogenic organising pneumonia (COP)
23. Symmetric bilateral infiltrates in LSSymmetric bilateral infiltrates in LS
CT confirmed dense patchy interstitialCT confirmed dense patchy interstitial
infiltratesinfiltrates
24. A: CXR: diffuse fine nodules. B: CT: widespread, bilateral fine micronodules. C, D:A: CXR: diffuse fine nodules. B: CT: widespread, bilateral fine micronodules. C, D:
lung biopsy: eosinophilic infiltration of alveolar spaceslung biopsy: eosinophilic infiltration of alveolar spaces
26. EPIDEMIOLOGYEPIDEMIOLOGY
Ancylostoma duodenaleAncylostoma duodenale oror Necator americanus:Necator americanus:
2 nematodes with similar LC2 nematodes with similar LC
• Humans are major reservoir. More in rural areas (soilHumans are major reservoir. More in rural areas (soil
contamination)contamination)
• Both are prevalentBoth are prevalent
• Larvae & eggs survive in loose, moist, shady, aerated,Larvae & eggs survive in loose, moist, shady, aerated,
warm soil (temp. 23–33°C)warm soil (temp. 23–33°C)
• Skin infestation occurs by larvaeSkin infestation occurs by larvae
• LC:LC: 4-12w4-12w
LC: life cycleLC: life cycle
27.
28. LIFE CYCLELIFE CYCLE
• Eggs in stool (1). Larvae hatch out in 1-2d in favorableEggs in stool (1). Larvae hatch out in 1-2d in favorable
moisture, warmth & shademoisture, warmth & shade
• Rhabditiform larvae grow (2) in 5-10d (2 molts)Rhabditiform larvae grow (2) in 5-10d (2 molts) ⇒⇒
filariform (infective) (3); can survive 3-4wfilariform (infective) (3); can survive 3-4w ⇒⇒ penetratepenetrate
skin & are carried to lungsskin & are carried to lungs ⇒⇒ ascend toascend to pharynxpharynx ⇒⇒ areare
swallowed (4)swallowed (4)
• The larvae reach small gut & mature to adultsThe larvae reach small gut & mature to adults ⇒⇒ attach toattach to
gut wall to suck blood (5)gut wall to suck blood (5)
• Worms can live 5-15y, but aWorms can live 5-15y, but a 70% decrease within 1-2y70% decrease within 1-2y
32. CL. MANIFESTATIONSCL. MANIFESTATIONS
MostlyMostly asymptomaticasymptomatic
• Common c/of IDA in L&MICsCommon c/of IDA in L&MICs
• Heavy load can cause malnutritionHeavy load can cause malnutrition
• Skin infestation (ground itch; usually feet): a stinging/Skin infestation (ground itch; usually feet): a stinging/
burning itchy papulovesicular rash ~1-2wburning itchy papulovesicular rash ~1-2w
• Löffler is uncommonLöffler is uncommon
• AP, NVD & marked eosinophiliaAP, NVD & marked eosinophilia
4-6w later4-6w later
33. DxDx
• Eggs in feces after 8-12w of infestationEggs in feces after 8-12w of infestation
• Adult worms rarely are seenAdult worms rarely are seen
HW eggs (HW eggs (AD/NAAD/NA cannot be DD). The embryo (right) has begun cellcannot be DD). The embryo (right) has begun cell
divisiondivision
34. TREATMENTTREATMENT
• Albendazole, mebendazole, pyrantel p. effectiveAlbendazole, mebendazole, pyrantel p. effective
• ½ adult dose of albendazole/mebendazole for <2y½ adult dose of albendazole/mebendazole for <2y
• In preg., deworm during 2In preg., deworm during 2ndnd
-3-3rdrd
TMTM
• Repeat stool exam., 2w laterRepeat stool exam., 2w later
• Retreat SOSRetreat SOS
• Supplementation with ironSupplementation with iron
35. CONTROL MEASURESCONTROL MEASURES
• Sanitary disposal of fecesSanitary disposal of feces
• Rx of all infested people & screening of children & farmRx of all infested people & screening of children & farm
workers in endemic areasworkers in endemic areas
• Wearing shoes & full dressWearing shoes & full dress
• Periodic dewormingPeriodic deworming
37. EPIDEMIOLOGYEPIDEMIOLOGY
• E vermicularisE vermicularis is ais a nematodenematode
• V. common worldwide.V. common worldwide. HumansHumans onlyonly
• Commonly as clusters of cases in familiesCommonly as clusters of cases in families
• More in small children, in caregiversMore in small children, in caregivers
• 50% institutionalized people may be infected50% institutionalized people may be infected
• Egg by fecal-oral route or contaminated hands/fomitesEgg by fecal-oral route or contaminated hands/fomites
• Females dieFemales die after laying eggs!after laying eggs!
• Eggs become infective in 2-3w. LC: 1-2 moEggs become infective in 2-3w. LC: 1-2 mo
38. CFCF
SpeciallySpecially adults areadults are asymptomaticasymptomatic
• May causeMay cause pruritus anipruritus ani && pruritus vulvaepruritus vulvae
• Frequency of micturitionFrequency of micturition
• Can be found in appendix, but cause no appendicitisCan be found in appendix, but cause no appendicitis
• Teeth grinding, wt. loss, enuresis are not from itTeeth grinding, wt. loss, enuresis are not from it
• Urethritis, vaginitis, salpingitis, or PID may occur fromUrethritis, vaginitis, salpingitis, or PID may occur from
migration of adult wormsmigration of adult worms
39. (1)(1) Eggs are deposited on perianal areas. (2)Eggs are deposited on perianal areas. (2) Self-infectionSelf-infection
occurs by ingesting eggs. P2P transmission throughoccurs by ingesting eggs. P2P transmission through
clothes/linens. Some eggs mayclothes/linens. Some eggs may becomebecome airborneairborne &&
swallowed. (3) From eggs, larvae hatch in small gut. (4)swallowed. (3) From eggs, larvae hatch in small gut. (4)
Adults settle in colon (2mo). (5) Gravid females comeAdults settle in colon (2mo). (5) Gravid females come
nocturnally outside & oviposit. Larvae inside eggsnocturnally outside & oviposit. Larvae inside eggs
develop (infective) in 4-6h (1)develop (infective) in 4-6h (1)
• LC:LC: 1mo1mo
• RetroinfectionRetroinfection (migration of new larvae from anal skin(migration of new larvae from anal skin
back into rectum), may occurback into rectum), may occur
LIFE CYCLELIFE CYCLE
40.
41.
42. DxDx
• Usually by seeing adults in perianum (best 2-3h after theUsually by seeing adults in perianum (best 2-3h after the
child is asleep)child is asleep)
• Very few ova are seen in stool; so, not recommendedVery few ova are seen in stool; so, not recommended
• Adhesive tapeAdhesive tape on perianal skin to collect eggs (90% in 3on perianal skin to collect eggs (90% in 3
consecutive samples) when pt. awakens in morningconsecutive samples) when pt. awakens in morning
• Anal swabsAnal swabs ("Swube tubes:" paddles coated with adhesive("Swube tubes:" paddles coated with adhesive
material) may also be usedmaterial) may also be used
45. Pinworm: adult in perianal area 2-3h after child goes asleepPinworm: adult in perianal area 2-3h after child goes asleep
46. TREATMENTTREATMENT
• DoC:DoC: mebendazole, pyrantel p., albendazole (single dose,mebendazole, pyrantel p., albendazole (single dose,
repeat after 2w). Full family Rx. is requiredrepeat after 2w). Full family Rx. is required
• Others: piperazine & pyrvinium pamoateOthers: piperazine & pyrvinium pamoate
• ReinfectionReinfection is v. common. Morning bath removes a largeis v. common. Morning bath removes a large
proportion of eggs. Frequently changing underwares,proportion of eggs. Frequently changing underwares,
bed linens may reduce egg load & decrease reinfectionbed linens may reduce egg load & decrease reinfection
• Hand washing, keeping nails short, avoiding scratching ofHand washing, keeping nails short, avoiding scratching of
perianal region & nail biting decreaseperianal region & nail biting decrease autoinfection &autoinfection &
transmissiontransmission
• Repeated infections are treated the same wayRepeated infections are treated the same way
47. CONTROLCONTROL
is difficult in child care centers & schools: high reinfectionis difficult in child care centers & schools: high reinfection
• Mass & simultaneous Rx, repeated after 2w, can beMass & simultaneous Rx, repeated after 2w, can be
effectiveeffective
• Good hand hygiene is the most effectiveGood hand hygiene is the most effective
49. ETIOLOGYETIOLOGY
T spiralisT spiralis
•5 species are capable of infecting.5 species are capable of infecting. TT spiralisspiralis is theis the
commonest c/of human inf.commonest c/of human inf.
50. EPIDEMIOLOGYEPIDEMIOLOGY
• It is enzootic worldwide in many carnivores, especiallyIt is enzootic worldwide in many carnivores, especially
scavengersscavengers
• Inf. occurs from ingestingInf. occurs from ingesting raw/insufficiently cooked meatraw/insufficiently cooked meat
containing encysted larvae ofcontaining encysted larvae of T spiralis.T spiralis. The usualThe usual
source of human inf. issource of human inf. is porkpork, but horse meat & wild, but horse meat & wild
carnivorous game, can be sources. Feeding pigscarnivorous game, can be sources. Feeding pigs uncookeduncooked
garbage perpetuates the cycle of inf.garbage perpetuates the cycle of inf.
• It is not transmitted from P2PIt is not transmitted from P2P
• IPIP usually is 1-2wusually is 1-2w
51. LIFE CYCLELIFE CYCLE
• Meat with encysted TS larvaeMeat with encysted TS larvae (1)(1). In stomach, larvae are. In stomach, larvae are
releasedreleased (2);(2); invade small gut wall, develop as adultsinvade small gut wall, develop as adults
(3)(3) (F 2.2 mm; M 1.2 mm; life span in small gut is 4w).(F 2.2 mm; M 1.2 mm; life span in small gut is 4w).
After 1w, the female release larvaeAfter 1w, the female release larvae (4)(4) that migrate tothat migrate to
striated muscles where they encyst in 4-5w (5). Larvaestriated muscles where they encyst in 4-5w (5). Larvae
may live formay live for several yearsseveral years
• Rodents mainly maintain endemicityRodents mainly maintain endemicity
• Humans are accidentally infectedHumans are accidentally infected
52.
53. CL. MANIFESTATIONSCL. MANIFESTATIONS
MostlyMostly inapparent.inapparent. But can beBut can be fulminantfulminant && fatal!fatal!
• Severity is proportional to the inf. loadSeverity is proportional to the inf. load
• In the 1In the 1stst
w of ingesting infected meat, a person may bew of ingesting infected meat, a person may be
asymptomatic/have abdo. discomfort, NVDasymptomatic/have abdo. discomfort, NVD
• 2-8w later, as larvae migrate into tissues, fever, myalgia,2-8w later, as larvae migrate into tissues, fever, myalgia,
periorbital edema, urticaria, conjunctival & subungualperiorbital edema, urticaria, conjunctival & subungual
hge. may develophge. may develop
• Larvae live in tissues for years; calcification of larvaeLarvae live in tissues for years; calcification of larvae
occurs within 6-24mo (on X-ray)occurs within 6-24mo (on X-ray)
• In severe inf. : myocarditis, neuropathy, pneumonitis canIn severe inf. : myocarditis, neuropathy, pneumonitis can
follow in 1-2mofollow in 1-2mo
54. TS larvae in skeletal muscleTS larvae in skeletal muscle
55. Trichinosis.Trichinosis.
Striking edema ofStriking edema of
face. A h/of eatingface. A h/of eating
of poorly cookedof poorly cooked
"hogs head“."hogs head“.
Periorbital edemaPeriorbital edema
& conjunctivitis& conjunctivitis
are commonlyare commonly
seenseen
59. DIAGNOSISDIAGNOSIS
• Eosinophilia (~70%), SS, dietary h/of, suggestiveEosinophilia (~70%), SS, dietary h/of, suggestive
• Raised muscle enzymes (CPK, LDH)Raised muscle enzymes (CPK, LDH)
• Encapsulated larvae in skeletal muscle biopsy (deltoid &Encapsulated larvae in skeletal muscle biopsy (deltoid &
gastrocnemius) 2w after infectiongastrocnemius) 2w after infection
• Serologic tests are available (CDC). S. antibody rarelySerologic tests are available (CDC). S. antibody rarely
positive before 2positive before 2ndnd
w of illnessw of illness
60. TREATMENTTREATMENT
• Mebendazole/albendazole effective; neither is veryMebendazole/albendazole effective; neither is very
effective foreffective for TT larvae in muscleslarvae in muscles
• Steroids with anthelmintic often is recommended when SSSteroids with anthelmintic often is recommended when SS
are severe. Steroids suppress inflam. & can beare severe. Steroids suppress inflam. & can be
lifesaving when CNS or heart is involvedlifesaving when CNS or heart is involved
61. CONTROL MEASURESCONTROL MEASURES
• Stop transmission to pigs by not feeding pigsStop transmission to pigs by not feeding pigs
garbagegarbage
• Effective rat controlEffective rat control
• Cook pork thoroughly (meat is no longer pink).Cook pork thoroughly (meat is no longer pink).
Freezing pork at -23°C x10d kills larvaeFreezing pork at -23°C x10d kills larvae
• People who have ingested contaminated meatPeople who have ingested contaminated meat
should be Rx with anthelminthshould be Rx with anthelminth
63. EPIDEMIOLOGYEPIDEMIOLOGY
• AA nematode.nematode. Endemic in tropics, subtropicsEndemic in tropics, subtropics
• Humans: principalHumans: principal reservoirsreservoirs. Also dogs, cats, other animals. Also dogs, cats, other animals
• TransmissionTransmission by penetration of skin by filariform larvaeby penetration of skin by filariform larvae
(soil/autoinfection)(soil/autoinfection) ⇒⇒ migrate to lungsmigrate to lungs ⇒⇒ ascend toascend to
bebe swallowedswallowed ⇒⇒ mature in wall of duodenum, jejunum &mature in wall of duodenum, jejunum &
colon to autoinfectcolon to autoinfect
• Adult females lay eggsAdult females lay eggs ⇒⇒ free-living rhabditiform larvae onfree-living rhabditiform larvae on
passing in feces. Autoinfection may make pt. infectedpassing in feces. Autoinfection may make pt. infected
for decades. In immunocompromised, autoinfectionfor decades. In immunocompromised, autoinfection
may cause hyperinfectionmay cause hyperinfection
64. Life cycleLife cycle
It is most complex among all helminths:It is most complex among all helminths:
• AlternateAlternate free-living & sexual cyclesfree-living & sexual cycles
• Potential for autoinfection & multiplication within the hostPotential for autoinfection & multiplication within the host
• 2 LC:2 LC:
65. Free-living cycleFree-living cycle
• Rhabditiform larvae passed in stool (1) can either moltRhabditiform larvae passed in stool (1) can either molt
x2 to become infective filariform (direct development)x2 to become infective filariform (direct development)
(6) or molt x4 & become free-living adult males &(6) or molt x4 & become free-living adult males &
females (2) & mate to produce eggs (3) from whichfemales (2) & mate to produce eggs (3) from which
rhabditiform larvae hatch (4) which in turn can eitherrhabditiform larvae hatch (4) which in turn can either
develop (5) into a new generation of free-living adultsdevelop (5) into a new generation of free-living adults oror
into infective filariform larvae (6)into infective filariform larvae (6)
• Filariform larvae enter human skin to initiate LCFilariform larvae enter human skin to initiate LC
66. Parasitic cycleParasitic cycle
• Filariform l. in soil penetrate skin (6)Filariform l. in soil penetrate skin (6) ⇒⇒ lungs (alveoli)lungs (alveoli) ⇒⇒
ascend to be swallowedascend to be swallowed ⇒⇒ small gut (7)small gut (7) ⇒⇒ molt x2 &molt x2 &
become adults (8). Females bybecome adults (8). Females by parthenogenesis canparthenogenesis can
produce eggs (9)produce eggs (9) ⇒⇒ rhabditiform l.: can either pass inrhabditiform l.: can either pass in
stool (1) or causestool (1) or cause autoinfectionautoinfection (10)(10)
• InIn autoinfectionautoinfection, filariform l., filariform l. ⇒⇒ penetrate either gutpenetrate either gut
mucosa (mucosa (internalinternal autoinfection) or perianal areaautoinfection) or perianal area
((externalexternal autoinfection). They follow the pulmonaryautoinfection). They follow the pulmonary
routeroute or may disseminate widelyor may disseminate widely
• Autoinfection explains persistent inf. for decades & ofAutoinfection explains persistent inf. for decades & of
hyperinfectionshyperinfections
67.
68. CL. MANIFESTATIONSCL. MANIFESTATIONS
• Can be asymptomaticCan be asymptomatic.. Eosinophilia only featureEosinophilia only feature
• Consider it in an endemic area if eosinophilia (>500/µL)Consider it in an endemic area if eosinophilia (>500/µL)
w/o obvious causew/o obvious cause
• Larval migration:Larval migration:
a)a) in lungs: pn., bloody, mucoid, voluminous sputumin lungs: pn., bloody, mucoid, voluminous sputum
b)b) from stool: itchy migrating, serpentine rashfrom stool: itchy migrating, serpentine rash
as tracks (as tracks (larva currens)larva currens)
• Intestinal phase:Intestinal phase: AP, distention, VD, hyperinfection,AP, distention, VD, hyperinfection,
septicemia/meningitis by enteric Gram-ve bacilli (moresepticemia/meningitis by enteric Gram-ve bacilli (more
in immunocompromised)in immunocompromised)
71. DIAGNOSISDIAGNOSIS
• Stool:Stool: typical larvae; several fresh samples needed. Concn.typical larvae; several fresh samples needed. Concn.
procedure may be requiredprocedure may be required
• Duodenal aspirate byDuodenal aspirate by Entero-Test/ endoscopic aspirateEntero-Test/ endoscopic aspirate
may show larvaemay show larvae
• SerodiagnosisSerodiagnosis seem to be most sensitive but do not DDseem to be most sensitive but do not DD
past & current inf. & false-negative occurspast & current inf. & false-negative occurs
• Sputum:Sputum: larvae can be found inlarvae can be found in hyperinfectionhyperinfection
• EosinophiliaEosinophilia (>500/µL) is common(>500/µL) is common
72. RxRx
• Ivermectin/thiabendazole is mostly curative. For heavy inf.Ivermectin/thiabendazole is mostly curative. For heavy inf.
ivermectin is DoCivermectin is DoC
• Rx may need repetition or prolonged in hyperinfection orRx may need repetition or prolonged in hyperinfection or
in immunocompromisedin immunocompromised
• Relapses are treated similarlyRelapses are treated similarly
73. CONTROL MEASURESCONTROL MEASURES
• Safe disposal of human wasteSafe disposal of human waste
• Education about inf. through bare skin is importantEducation about inf. through bare skin is important
• Immunocompromized & pt. in endemic area: exclude itImmunocompromized & pt. in endemic area: exclude it
before immunosuppressive Rx. For immediatebefore immunosuppressive Rx. For immediate
immunosuppressive Rx: empiric Rx must be consideredimmunosuppressive Rx: empiric Rx must be considered
74. Peculiarities ofPeculiarities of S stercoralisS stercoralis
• Can lead both free-living & parasitic cyclesCan lead both free-living & parasitic cycles
• Females can produce eggs byFemales can produce eggs by parthenogenesisparthenogenesis
• Transmission by larvaeTransmission by larvae
• Penetrate intact skinPenetrate intact skin
• Autoinfection: maintain for decadesAutoinfection: maintain for decades
• HyperinfectionHyperinfection
Intact skin penetration:Intact skin penetration: S. stercoralis, Hookworms, Gonococcus,S. stercoralis, Hookworms, Gonococcus,
Leptospira, Syphilis,Leptospira, Syphilis,
78. • WhipwormWhipworm is 3is 3rdrd
commonest nematode: more in areascommonest nematode: more in areas
where human feces is used as manure or of poorwhere human feces is used as manure or of poor
sanitation. Fecal-oral transmissionsanitation. Fecal-oral transmission
• Worldwide, more in tropics, among childrenWorldwide, more in tropics, among children
• 1 billion cases1 billion cases
CF:CF:
• Light/heavy inf. May beLight/heavy inf. May be asymptaticasymptatic
• Dysenteric stoolsDysenteric stools (may be chr., mimicking IBD),(may be chr., mimicking IBD), tenesmus,tenesmus,
AP, distention,AP, distention, rectal prolapse,rectal prolapse, appendicitis, urticaria,appendicitis, urticaria,
severe anemia, FTT, impaired cognitionsevere anemia, FTT, impaired cognition
79.
80. LCLC
• Immature eggs are passed in stoolImmature eggs are passed in stool ⇒⇒ develop in soil intodevelop in soil into
2-cell stage2-cell stage ⇒⇒ embryonatedembryonated ⇒⇒ infective (15-30d)infective (15-30d) ⇒⇒
ingestion (soil, hands or food)ingestion (soil, hands or food) ⇒⇒ larvae hatch in smalllarvae hatch in small
gutgut ⇒⇒ mature as adults in colonmature as adults in colon
• Adults (4cm) live in cecum & ascending colon with anteriorAdults (4cm) live in cecum & ascending colon with anterior
portions threaded into mucosaportions threaded into mucosa
• Females oviposit 60-70d after inf. 3,000-20,000 eggs/dFemales oviposit 60-70d after inf. 3,000-20,000 eggs/d
• Live about 1yLive about 1y
81.
82. DiagnosisDiagnosis
• Eggs in stool: concn.Eggs in stool: concn.
method bettermethod better
• EndoscopyEndoscopy
• Eosinophilia, IDAEosinophilia, IDA
TreatmentTreatment
• Albendazole/mebendazole are DoCAlbendazole/mebendazole are DoC
• Repeat stool examRepeat stool exam
• Iron supplements for anemiaIron supplements for anemia
83. Prevention & ControlPrevention & Control
• Avoid ingesting soilAvoid ingesting soil
• Wash hands before handling foodWash hands before handling food
• Wash, peel, or cook all raw vegetables beforeWash, peel, or cook all raw vegetables before
eating, particularly those that have been growneating, particularly those that have been grown
in soil that has been fertilized with manure.in soil that has been fertilized with manure.
85. • E granulosusE granulosus causescauses cystic echinococcosis (CE):cystic echinococcosis (CE):
most frequently encountered. Itmost frequently encountered. It causescauses
hydatidosis, or hydatid disease/cyst) by thehydatidosis, or hydatid disease/cyst) by the
larval stages oflarval stages of EchinococcusEchinococcus
• E multilocularisE multilocularis causescauses alveolar echinococcosis (AE)alveolar echinococcosis (AE)
• E vogeliE vogeli causes polycystic echinococcosiscauses polycystic echinococcosis
• E oligarthrusE oligarthrus is extremely rareis extremely rare
86. LCLC
• AdultAdult E granulosusE granulosus (3-6mm) lives in small gut of definitive(3-6mm) lives in small gut of definitive
hosts (dogs or other canids). Gravid proglottids releasehosts (dogs or other canids). Gravid proglottids release
eggseggs ⇒⇒ in fecesin feces ⇒⇒ ingested by intermediate hostingested by intermediate host
(sheep, goat, swine, cattle, camel)(sheep, goat, swine, cattle, camel) ⇒⇒ oncosphereoncosphere
hatches in small guthatches in small gut ⇒⇒ penetrates gut wallpenetrates gut wall ⇒⇒ migratesmigrates
into organs (liver, lungs)into organs (liver, lungs) ⇒⇒ cyst (enlarges gradually)cyst (enlarges gradually)
producing protoscolices & daughter cysts that fill cystproducing protoscolices & daughter cysts that fill cyst
• Definitive host is infected by ingesting the cyst ofDefinitive host is infected by ingesting the cyst of
intermediate hostintermediate host ⇒⇒ protoscolices evaginate gutprotoscolices evaginate gut
mucosamucosa ⇒⇒ develop as adults (32-80d)develop as adults (32-80d)
• LCLC ofof E. multilocularisE. multilocularis is similar; some differencesis similar; some differences
87.
88. Cystic echinocccosis (CE)Cystic echinocccosis (CE)
or hydatid D, is c/by larvae ofor hydatid D, is c/by larvae of E granulosusE granulosus. Most inf. in. Most inf. in
humans arehumans are asymptomaticasymptomatic,, CECE causes harmful, slowlycauses harmful, slowly
enlarging cysts in liver, lungs, other organs (neglectedenlarging cysts in liver, lungs, other organs (neglected forfor
years)years)
• Alveolar echinococcosis (AE):Alveolar echinococcosis (AE): by larvae ofby larvae of EE
multilocularismultilocularis, smaller, found in foxes, coyotes, & dogs., smaller, found in foxes, coyotes, & dogs.
Small rodents are intermediate HSmall rodents are intermediate H.. Although cases ofAlthough cases of
AE in animals in endemic areas are relatively common,AE in animals in endemic areas are relatively common,
human cases are rare. AE poses a much greater healthhuman cases are rare. AE poses a much greater health
threat than CE: parasitic tumors in liver, lungs, brain,threat than CE: parasitic tumors in liver, lungs, brain,
other organs; can be fatalother organs; can be fatal
89. • CECE is found in Africa, Europe, Asia, ME, C. & S. Americas.is found in Africa, Europe, Asia, ME, C. & S. Americas.
Dogs get it when ingest organs having HC & developDogs get it when ingest organs having HC & develop
adult tapeworms in gut. Infected dogs shed eggs.adult tapeworms in gut. Infected dogs shed eggs.
Sheep, cattle, pigs ingest eggs that hatch & developSheep, cattle, pigs ingest eggs that hatch & develop intointo
cysts in organs. The commonest transmission tocysts in organs. The commonest transmission to
humans is by accidental consumption of eggs in soilhumans is by accidental consumption of eggs in soil
(viable for a year)(viable for a year)
• Most commonly found in people who raise sheep.Most commonly found in people who raise sheep.
Working dogs when allowed to eat the offal of inf.Working dogs when allowed to eat the offal of inf.
sheep spread the diseasesheep spread the disease
90. L to R: E granulosus adult. Close-up of the scolex of E.
granulosus. One of the suckers is clearly visible, as is the ring of
rostellar hooks
91. CFCF
• CE often isCE often is asymptomaticasymptomatic until big (several years)until big (several years)
to cause discomfort, pain, NV. SS typicallyto cause discomfort, pain, NV. SS typically
depends on the locationdepends on the location
• Mainly found in liver & lungs but can appear inMainly found in liver & lungs but can appear in
other places. Cyst if ruptures (trauma) mayother places. Cyst if ruptures (trauma) may
cause mild to severe anaphylaxis, even death,cause mild to severe anaphylaxis, even death, as aas a
result of the release of cystic fluidresult of the release of cystic fluid
92.
93. DxDx
• Presence of cyst-like mass with h/of exposure toPresence of cyst-like mass with h/of exposure to
sheepdogs in an endemic suggests Dxsheepdogs in an endemic suggests Dx
• Imaging: CT, USG, MRIs are usefulImaging: CT, USG, MRIs are useful
• Serologic tests to confirmSerologic tests to confirm
94. RxRx
• Surgery was only Rx. Chemotherapy, cyst puncture,Surgery was only Rx. Chemotherapy, cyst puncture,
& PAIR (percutaneous aspiration, injection of& PAIR (percutaneous aspiration, injection of
chemicals & re-aspiration) have replacedchemicals & re-aspiration) have replaced
surgerysurgery
• But surgery remains the most effective Rx toBut surgery remains the most effective Rx to
remove it for complete cureremove it for complete cure
• Silent cysts often go away without RxSilent cysts often go away without Rx
95. Site of Infestation of WormsSite of Infestation of Worms
• Small gut:Small gut: A.L., hookworms,A.L., hookworms, TT spiralis (adults), S.spiralis (adults), S.
stercoralisstercoralis
• Colon:Colon: pin worms, S stercoralis (larvae),pin worms, S stercoralis (larvae),
hookworms,hookworms, whipwormwhipworm
• Striated muscles:Striated muscles: TT spiralisspiralis
• Extra intestine:Extra intestine: echinococcusechinococcus
96. PreventionPrevention
• Limiting areas for dog. Prevent it eating infectedLimiting areas for dog. Prevent it eating infected
meat, carcasses of infected sheepmeat, carcasses of infected sheep
• Control stray dog. Wash hands after touching dogs,Control stray dog. Wash hands after touching dogs,
before handling foodbefore handling food
• Teach children washing handsTeach children washing hands
• Restrict home slaughter of livestockRestrict home slaughter of livestock
• Do not eat food/water ?contaminated by dog fecesDo not eat food/water ?contaminated by dog feces
97. ANTI-HELMINTHICSANTI-HELMINTHICS (vermicide, vermifuge)(vermicide, vermifuge)
• MEBENDAZOLE.MEBENDAZOLE. blocks glucose uptake & depletesblocks glucose uptake & depletes
glycogen. Acts against:glycogen. Acts against: AL, EV, AD,TT,AL, EV, AD,TT, Tapeworm,Tapeworm,
Hydatid cyst, NeurocysticercosisHydatid cyst, Neurocysticercosis
SE:SE: NVD, allergy, loss of hair, granulocytopeniaNVD, allergy, loss of hair, granulocytopenia
Dose:Dose: 100mg BD x 3d. Enterobius:100mg once,100mg BD x 3d. Enterobius:100mg once,
repeated after 2wrepeated after 2w
• ALBENDAZOLE:ALBENDAZOLE: congener of mebendazole. Single dose.congener of mebendazole. Single dose.
Acts against:Acts against: AL, EV, AD,TT,AL, EV, AD,TT, Tapeworm, Hydatid D,Tapeworm, Hydatid D,
Neurocysticercosis, filariasisNeurocysticercosis, filariasis
SE:SE: well tolerated, dizziness. Prolonged use: HA, F,well tolerated, dizziness. Prolonged use: HA, F,
alopecia, jaundice, neutropeniaalopecia, jaundice, neutropenia
98. • Pyrantel palmoate. APyrantel palmoate. Against AL, EV, AD, comparablegainst AL, EV, AD, comparable
to mebendazole. Causes spastic paralysis.to mebendazole. Causes spastic paralysis.
Remarkably free of SE, tasteless, non irritant,Remarkably free of SE, tasteless, non irritant,
abnormal migration of worms is not seenabnormal migration of worms is not seen
Dose: 11mg/kg (not >g)
• DEC.DEC. Highly selective effect on microfilariae. AltersHighly selective effect on microfilariae. Alters
Mf membraneMf membrane ⇒⇒readily phagocytosed Uses:readily phagocytosed Uses:
Filariasis:2mg/kg TDS. Mf clears from blood inFilariasis:2mg/kg TDS. Mf clears from blood in
7d. Radical cure by 12d-3w. Tropical7d. Radical cure by 12d-3w. Tropical
eosinophilia: 2-4mg/kg TDS for 2-3weosinophilia: 2-4mg/kg TDS for 2-3w
SE:SE: ANV, dizziness, F, rash, pruritus, LAP & fall inANV, dizziness, F, rash, pruritus, LAP & fall in
BP may occur due to mass destruction of Mf &BP may occur due to mass destruction of Mf &
adult wormsadult worms
99. • Piperazine.Piperazine. Not used now a days. CI: neurological dNot used now a days. CI: neurological d
• Niclosamide.Niclosamide. DoC for tapeworms (DoC for tapeworms (T saginata, H nana, FT saginata, H nana, F
buski, H heterophyesbuski, H heterophyes))
It kills the head of the tapeworm (inhibit oxidativeIt kills the head of the tapeworm (inhibit oxidative
phosphorylation). Dose: 1-3 tab (500mg)phosphorylation). Dose: 1-3 tab (500mg)
• Ivermectin DoCIvermectin DoC in SS,in SS, O volvulus. Also forO volvulus. Also for scabies, Filariasisscabies, Filariasis
& cutaneous larvae migrans. Paralyze& cutaneous larvae migrans. Paralyze nematodes &nematodes &
arthropods. Dose: single, 150-200mcg/kgarthropods. Dose: single, 150-200mcg/kg
• PraziquantelPraziquantel effective in Schistosomiasis & most flukes. Alsoeffective in Schistosomiasis & most flukes. Also
used against Taeniasis, Diphyllobothriasis, &used against Taeniasis, Diphyllobothriasis, &
neurocysticercosisneurocysticercosis
• Levamisole: not used as anthelminticLevamisole: not used as anthelmintic
100. MCQMCQ
• Only ascaris as worm can cause intes. obstructionOnly ascaris as worm can cause intes. obstruction
• S stercoralisS stercoralis can cause hyperinfectioncan cause hyperinfection
• Ivermectin is an anthelmintic & anti-scabiesIvermectin is an anthelmintic & anti-scabies
• T trichiuriaT trichiuria can cause Loeffler Syn.can cause Loeffler Syn.
• HW infestation is an imp. cause of IDAHW infestation is an imp. cause of IDA
101. MCQMCQ
• HW inf. occurs by swallowing eggsHW inf. occurs by swallowing eggs
• Rhabditiform larva is usually infectiveRhabditiform larva is usually infective
• TT can cause rectal prolapseTT can cause rectal prolapse
• Female parasite is usually largerFemale parasite is usually larger
• S. stercoralis can be free livingS. stercoralis can be free living
102. • For all worm infestation we need full family RxFor all worm infestation we need full family Rx
• E vermicularisE vermicularis infestsinfests humanshumans onlyonly
• Teeth grinding (bruxism) is an imp. symptom ofTeeth grinding (bruxism) is an imp. symptom of
worm infestationworm infestation
• Pruritus aniPruritus ani && pruritus vulvae are imp. symptoms ofpruritus vulvae are imp. symptoms of
hookworm infestationhookworm infestation
• TT spiralis larvaespiralis larvae invade skeletal musclesinvade skeletal muscles
MCQMCQ
Hinweis der Redaktion
Parasite is an organism which lives in or on another organism (host) & benefits by deriving nutrients at the other&apos;s expense
Helminth is a parasite; large multicellular, can generally be seen with the naked eye when mature
Lice, bacteria & viruses are examples of parasites
Disability-adjusted life year (DALY) is a measure of overall d. burden, expressed as the number of years lost due to ill-health, disability or early death. It was developed as a way of comparing the overall health & life expectancy of different countries
Löffler syn is a transient resp illness a/with eosinophilia & XR changes. It is 1 of the 5 pulmonary eosinophilias (below). Original description was with AL as its most common cause; but, other parasites & ac. Hypersensitivity to drugs are included
Pulmonary Eosinophilia a/with tissue and/or blood eosinophilia is heterogeneous. It may be extrinsic or intrinsic. Some SS overlap. Inhaled or ingested drugs & parasites, fungi, mycobacteria may trigger it. It may be mild & self-limited, as in Loeffler syn. Intrinsic causes are generally idiopathic: a diverse group of autoimmune & idiopathic syn (blood dyscrasias, vasculitis). This group includes chr eosinophilic pneumonia (CEP), idiopathic hypereosinophilic syn (IHES), Churg-Strauss syn (CSS), & eosinophilic granuloma (EG; pulmonary histiocytosis X or Langerhans cell granulomatosis). Eosinophilia & pulmonary infiltrates have been reported in AIDS, lymphoma, a variety of inflam lung d, & collagen vascular d. Asthma may have marked eosinophilia, with/-out infiltrates.
COPD is largely neutrophilic, but 20-40% sputum has eosinophilia, a/with raised sputum interleukin (IL)–5
Eosinophilic bronchitis without asthma (EBWA) is characterized by cough for at least 2mo, a sputum eosinophil count &gt;3%, & no evidence of airway obs. Affected pts. are usually middle-aged, are nonatopic, & have no history of smoking. Activation & eosinophilic infiltration of the superficial airway occurs, rather than of airway smooth muscle
Eosinophilia may often be seen in the bronchoalveolar lavage in desquamative interstitial pneumonitis
Atopy: genetic tendency to dev allergic d like allergic rhinitis, asthma & atopic eczema. It is typically a/with heightened immune responses to common allergens, especially inhaled allergens & food allergens
HW
Ground itch refers to the inflam. reaction resulting from certain worms invasions into the skin: threadworms, S stercoralis, A duodenale, N americanus, A braziliense
Cutaneous larva migrans (CLM) is a rather common self-limiting nematode inf (usually animal hookworms). Inf via human hookworms is &quot;ground itch. The larval form is able to penetrate the epidermis where the inf is usually confined. Exposure & travel history is v imp. Clinical history is significant for exposure to sandy beaches or soil in warm (tropical or subtropical) climates. Sometimes pts will recall a prickling or burning sensation 30 min following larva penetration. IP is usually days but can be several weeks. CLM occurs worldwide. Inf from animal HW is common in the southeastern US, Mexico, Caribbean, Central and S America, SEA, Africa, and other tropical countries. Commonly affected areas are the feet & interdigital webs of the toes (from walking on the beach) as well as the buttocks and thighs (from sitting on the beach). It can also affect any area of the body.
Characteristic findings are extreme pruritus. Each larva produces a linear serpiginous reddish inflam 2-3mm wide tract, which advances by 1-2cm/d. These tracts may appear as coalescent papules or vesicles & can measure 20cm long. Pruritic follicular papules and pustules (2-5 mm) on the buttocks or thighs in conjunction with serpiginous tracts may be found. Vesicles and bullae are not uncommon. Nons. localized dermatitis may be present
Pyrantel is used to treat ascariasis, HW, pinworm, trichostrongyliasis, and trichinellosis. SE: nausea, HA, dizziness, trouble sleeping, and rash. A lower dose is used in liver d. It is not harmful during pregnancy. It is unclear if it is safe for use during breastfeeding. It works by paralyzing worms. It is on the WHO Essential Medicines, the most effective and safe medicines needed. It is cheap. It may also be used to treat worms in animals
Pruritus ani. The intensity of anal itching increases from moisture, pressure, and rubbing c/by clothing and sitting. At worst, anal itching causes intolerable discomfort that often is accompanied by burning and soreness. It is estimated that up to 5% of the population of the US experiences this type of discomfort daily.
Causes
If a specific cause for pruritus ani is found it is classified as &quot;secondary pruritus ani&quot;. If a specific cause is NOT found it is classified as &quot;idiopathic pruritus ani&quot;.[3] The irritation can be caused by intestinal parasites, anal perspiration, frequent liquid stools, diarrhea, residual stool deposits, or the escape of small amounts of stool as a result of incontinence or flatulence. Another cause is yeast infection or candidiasis. Some diseases increase the possibility of yeast infections, such as diabetes mellitus or HIV infection. Treatment with antibiotics can bring about a disturbance of the natural balance of intestinal flora, and lead to perianal thrush, a yeast infection affecting the anus. Psoriasis also can be present in the anal area and cause irritation. Abnormal passageways (fistulas) from the small intestine or colon to the skin surrounding the anus can form as a result of disease (such as Crohn&apos;s disease), acting as channels which may allow leakage of irritating fluids to the anal area. Other problems that can contribute to anal itching include pinworms, hemorrhoids, tears of the anal skin near the mucocutaneous junction (fissures), and skin tags (abnormal local growth of anal skin). Aside from diseases relative to the condition, a common view suggests that the initial cause of the itch may have passed, and that the illness is in fact prolonged by what is known as an itch-scratch-itch cycle.[4][5] It states that scratching the itch encourages the release of inflammatory chemicals, which worsen redness, intensifies itchiness and increases the area covered by dry skin, thereby causing a snowball effect.
Some authorities describe “psychogenic pruritus” or &quot;functional itch disorder&quot;,[6] where psychological factors may contribute to awareness of itching.
Ingestion of helminth (worm) Enterobius vermicularis (pinworm, or threadworm) eggs leads to enterobiasis, indicative of severe itching around the anus from migration of gravid females from the bowel. Severe cases of enterobiasis result in hemorrhage and eczema.
Treatment[edit]
The goal of treatment is asymptomatic, intact, dry, clean perianal skin with reversal of morphological changes. For pruritus ani of unknown cause (idiopathic pruritus ani)[3] treatment typically begins with measures to reduce irritation and trauma to the perianal area.[7] Stool softeners can help prevent constipation.[7] If this is not effective topical steroids or injected methylene blue may be tried. Another treatment option that has been met with success in small-scale trials is the application of a very mild (.006) topical capsaicin cream.[8] This strength cream is not typically commercially available and therefore must be diluted by a pharmacist or end-user. If the itchiness is secondary to another condition such as infection or psoriasis these are typically treated.[7]
A successful treatment option for chronic idiopathic pruritus ani has been documented using a clean, dry and apply (if necessary) methodology. The person is instructed to follow this procedure every time the urge to scratch occurs. The treatment makes the assumption that there is an unidentified bacteria in the feces that causes irritation and itching when the feces makes contact with the anal and perianal skin during defecation, flatulation or anal leakage (particularly during sleep).
Cleaning the area with warm water, avoiding all soaps and even baby wipes, then drying the area, ideally with a hair dryer to avoid irritation or failing that simply patting gently with a clean, dry, towel. If persons with pruritus ani do not need to scratch after these steps they are instructed to do nothing else. If the urge to scratch is still present they are instructed to apply a topical steroid cream which has antibiotic and antifungal properties. This will address a skin condition which may have become infected. Apply such a cream as directed by your medical professional but usually twice a day for one to two weeks. After this, they must maintain their clean and dry regime and apply an emollient ointment (not cream) to moisturize the skin. This should be applied after each bowel movement and at night. Continue until no longer needed. At any time, persons may use antihistamine treatments orally, to control the itching.[citation needed]
In case of long-lasting symptoms, above all in patients over 50 years of age, a colonoscopy is useful to rule out a colonic polyp or tumor, that can show pruritus ani as first symptom
Pruritus vulvae is the counterpart of pruritus scroti, and may have many different causes. Patch testing may be used to Dx the cause.
Causes: a symptom of an underlying condition more often than it is a primary condition. Vulva irritation can be caused by any moisture left on the skin. This moisture may be perspiration, urine, vaginal discharge or small amounts of stool. It may be caused by vaginal infections, vulvitis, HPV (human papilloma virus) infection, anal incontinence, Bowen&apos;s disease, or dietary irritants (caffeine, potatoes, chilli, capsicum, tomatoes, and peanuts).
Treatment with antibiotics can lead to a yeast infection and irritation of the vulva. Some diseases increase the possibility of yeast infections, such as diabetes mellitus.
Chronic inflammation of the vulva predisposes to the development of premalignant or malignant changes
LC threadworm
Enzootic: Endemic in animals. An enzootic d is constantly present in an animal population, but usually only affects a small number of animals at any one time
Scavengers: An animal, such as a vulture or housefly, that feeds on dead or decaying matter
Cutaneous Larva Migrans
Cutaneous larva migrans presents with serpiginous migratory papules due to the movement of hookworm larvae in the skin.
Pruritus is a cardinal feature.
The diagnosis is made clinically.
Oral ivermectin is the first-line treatment.
Introduction
Cutaneous larva migrans (CLM or creeping eruption) is a condition caused by the presence of hookworm larvae in the skin of humans, an accidental (non-definitive) host for this organism. Generally, unlike in the definitive hosts (dogs or cats), the larva is not able to penetrate the dermis and complete its life cycle of visceral organ involvement and thus remains confined to the epidermis. The larva’s migration through the epidermis prior to dying leads to hypersensitivity with often severe accompanying pruritus. Clinically this condition presents with a papule appearing a few hours to days after larval penetration followed by the appearance of migratory papules and/or vesicles in an arcuate and serpiginous configuration corresponding to the movement of the larva in the skin. The most frequent location is the lower extremities, with anogenital, truncal and upper extremity involvement being less common. The causative organisms are endemic to tropical and subtropical areas including Southeast Asia, the southeastern United States, Caribbean, South America, and Africa.
Larvae of the dog and cat hookworm, Ancylostoma braziliense are the most common cause of this condition. Less common causative organisms include the hookworm Ancylostoma caninum and Uncinaria stenocephala. The larvae hatch in the soil after the eggs are released in the feces of their animal hosts. Individuals at highest risk of being affected include travelers to endemic regions, swimmers and fishermen, children, outdoor laborers and farmers.
Initial Evaluation
Cutaneous Larva Migrans
The diagnosis of cutaneous larva migrans is generally made clinically, based upon the typical morphology of a serpiginous eruption and associated pruritus in a patient with a relevant exposure history. The typical rate of migration of the serpiginous lesion is approximately 1-2 cm per day. Because the location of the organism is not readily apparent and often a few centimeters proximal to the visible eruption, biopsy is not generally helpful diagnostically. While a peripheral eosinophilia is seen in a minority of patients, it is not necessary in confirming the diagnosis.
Differential diagnosis
Larva currensGnathostomasisLoaiasisCutaneous pili migrans
Tinea corporisAllergic contact dermatitis (acute)
Treatment
Cutaneous Larva Migrans
Cutaneous larva migrans is usually a self-limiting condition however, untreated cases, especially if extensive, may last for months to years or become bacterially superinfected. The therapeutic strategy is to eliminate the pathogenic organism. Pruritus symptoms typically resolve within a week after treatment, while the visible rash may take longer to resolve.
First steps
Oral ivermectin 200 mcg/kg once, or two doses on successive days.
Alternative steps
Albendazole 400 mg daily for 3-7 days, depending on the severity of the disease (3 days for single lesions, 5-7 days for multifocal disease). Albendazole is preferred over thiabendazole because of the significantly lower rates of GI upset.
Compounded topical preparations (if available) such as thiabendazole 15% ointment or cream applied three times daily for 5-10 days or 10% albendazole ointment three times daily for 10 days.
Antihistamines may be helpful adjunctively for severe pruritus.
Subsequent steps
About 90% of patients will be cured with the above regimens. Patients failing to improve after the initial dose(s) of ivermectin should have a second or third dose of 200 mcg/kg as required every two weeks.
Patients failing to improve with topical thiabendazole or oral albendazole should be treated with ivermectin.
Pitfalls
Despite the high success rates from the above regimens, at least 5% of patients, especially those with more widespread disease, may require more prolonged or repeated courses of treatment. Relapses may occur up to 30 days following treatment.
Failure of standard therapies to cure CLM may indicate underlying immunosuppression
Superinfection: new inf in a preexisting inf; e.g., bacterial inf. may occur in viral URTI, or a chr HBV carrier may be inf with HDV. Superinf can complicate the course of ABT when the organisms causing the new inf are resistant to the drugs being used to treat the first inf.
Hyperinfection: Inf by large numbers of organisms as a result of immunologicdeficiency
Larva Currens
is a fast-moving serpiginous eruption due to skin penetration by larvae of S stercoralis. In contrast to cut. larva migrans, the larvae here, travel much more quickly through the skin and are more likely to spread hematogenously to the resp. system. In immune compromised hosts, autoinfection can lead to elevated larval burden with potential fatal outcome (hyperinfection syn).
Larva currens (“running” larva) is caused by intestinal infection with Strongyloides stercoralis, a parasitic nematode that, uniquely, can complete its entire life cycle within a human host. This organism is endemic to the tropics and subtropics and is acquired via skin penetration by infectious filariform larvae, typically by contact with soil contaminated with human feces. Patients present with serpiginous erythematous papules coalescing into urticarial linear plaques on the feet (most commonly), buttocks, upper thighs, and lower abdomen due to movement within the dermis of these larvae. In contrast to cutaneous larva migrans, the rate of migration is faster at five or more centimeters per hour (compared to 1-2 cm per day in cutaneous larva migrans).
The filariform larvae, after entering the skin, can travel via hematogenous spread to the respiratory system. From there they travel to the upper airways and are swallowed, traveling thereby to the digestive tract where they mature and lay eggs which are excreted in the feces in order to complete the life cycle. In immune compromised hosts, the larvae can undergo autoinfection whereby they re-infect the same host by burrowing into the intestinal wall or peri-anal skin, which can lead to a dramatic increase in the burden of organisms in a single host (known as hyperinfection). In this situation, patients may present with purpuric lesions on the abdomen (classically in a periumbilical distribution) due to massive larval migration within the skin. This situation may present with severe systemic manifestations and septic shock. Eosinophilia is often but not always present.
Initial Evaluation
Larva Currens
Strongyloidiasis is most commonly diagnosed via stool examination for larvae (of note, standard methods are of low sensitivity due to intermittent larval excretion and therefore modified techniques, such as specimen concentration, are used to increase diagnostic yield) or serology (ELISA for IgG). Stool tests become positive approximately three to four weeks after the organism first enters the dermis. In cases of dissemination, larvae may be found in a wide variety of body fluids. Larvae may also be seen in lesional skin biopsies. Eosinophilia is also common, though a nonspecific finding.
Differential diagnosis
Similar to that of cutaneous larva migrans (see Differential diagnosis in Cutaneous Larva Migrans).
Diagnosis may be made by stool examination, serology, or skin biopsy.
Ivermectin for 2d is the DoC for uncomplicated inf, while dissemination and hyperinfection require longer Rx and follow-up to confirm clearance.
Treatment
Larva Currens
First steps
Ivermectin 200 mcg/kg usually given in two doses on two consecutive days.
Alternative steps
Albendazole 400 mg twice daily for 3-7 days.
Subsequent steps
In immune compromised patients with disseminated disease, reducing the degree of immune suppression as much as feasible may be helpful, along with multiple doses of ivermectin (one dose per day for one week, e.g., for 3-7 days) until symptoms resolve (and potentially until stool ova and parasite examinations remain negative for at least two weeks).
If initial stool exams are positive, stool exams to confirm clearance are recommended approximately two to four weeks after treatment is complete. In patients with hyperinfection, daily stool exams are obtained for at least two weeks after treatment to confirm clearance (alternatively, serology titers may be rechecked at 3-6 months after treatment to confirm clearance).
Pitfalls
Albendazole has a lower cure rate in strongyloidiasis and should not be used as first-line therapy.
Patients with stronglyloides hyperinfection syndrome are prone to developing potentially fatal gram-negative sepsis due to translocation of gut bacteria—an index of suspicion for this should be maintained, with blood cultures checked and empiric broad spectrum antibiotics used in appropriate cases.
Subsequent steps
Patients failing to improve on short courses of ivermectin should have longer courses or repeat courses at 10- to 14-day intervals
Case
26-year-old woman, no significant past medical history
Review of systems negative
Presents for evaluation of one-week history of very itchy rash on foot that seems to be slowly moving, recently returned from backpacking trip in Southeast Asia
Initial evaluation
Healthy appearing young woman
Serpiginous eruption of papules and vesicles in a linear arrangement on right dorsal foot
Diagnosis: Cutaneous larva migrans
Clinical diagnosis based on morphology and exposure history
Treatment
Oral ivermectin 200 mcg/kg in a single dose
Hydroxyzine 10-20 mg at bedtime for pruritus as needed
Follow-up evaluation
Patient reports resolution of itch and partial fading of rash a week later. No further movement of lesions is noted
Patient is followed up to ensure complete resolution one month later
Oncosphere: 1 of the larval stages of most tapeworms. The body is spherical with three pairs of chitinous hooks; hence, an oncosphereis often called a hexacanth—literally, a six-hooked embryo.
The oncosphere develops within an egg inside the worm’s uterus. The egg then leaves the body of the host in the host’s feces. The oncosphere continues to develop in water Or in the body ofan intermediate host
Scolex. pl. scolices. The knoblike anterior end of a tapeworm, having suckers or hook like parts that in the adult stage serve as organs of attachment to the host.
[skōlēx, worm
Bruxism: involuntary habitual grinding of the teeth, typically during sleep
