soft tissue infections

1. Skin and Soft Tissue
Infections

2. • Infections in,
– Skin
– Subcutaneous
tissue
– Fasciae
– Muscles

4. Erysipel
as
• Strep. Infections of dermis
• Well demarcated,
painful, erythematous
• indurated plaques, Blisters
& ulceration 
• Abrupt fever with chills
• Face, legs
• common in very young,
old, debilitated patients
• lymphoedematous
• erysipelas and Cellulitis
overlap often
• Treatment: Penicillin IV/IM

5. Impetig
o
• A contagious superficial infection of the skin
• Staphylococci or β-haemolytic streptococci
• common in children
• usually involves the skin of the face, often around
the mouth and nose.
• spread by direct contact
• Minor abrasions and other skin lesions
predispose to infections
• Prevention is by good personal hygiene ,
particularly hand washing with soap.

6. • It has two forms:
1. Non-bullous
Streptococcus
pyogenes
"honey-crust" lesions
2. Bullous
Staphylococcus
aureus
rupture of the bullae
"varnish-like" crust

8. Treatmen
t
• Usually self-limiting
• Avoid precipitating factor (e.g.,
exfoliation)
• Localized
– topical fusidic acid tds. (for
MRSA)
• mild and localized – Topical antibiotic
e.g.; topical
mupirocin

9. • Other close contacts should be
examined
• children should avoid school for 1week
after starting therapy.
• resistant to treatment or recurrent
–take nasal swabs and check other
family members.
• Eradication of nasal carriage
–Nasal mupirocin

10. Folliculiti
s
• Infections of the
superficial part of
the hair follicle
• itchy or tender
papules and
pustules.
• Staphylococcus
aureus

11. • Small pustules
often pierced by a
hair
• Legs, face –
(sycosis barbae)
• commoner in humid
climates and when
occlusive clothes are
worn.
• Extensive, itchy
folliculitis in HIV
infection.

12. Treatmen
t
• topical antiseptics
• topical sodium fusidate
• mupirocin containing ointment
• oral antibiotics
– flucloxacillin or erythromycin
• If chronic – Detect and treat carrier
state

13. Boils
(furuncles)
• Staph. Infections of the deeper part of hair follicle
• most common on the face, neck, armpit, buttocks,
and thighs
• On central face
– danger of cavernous sinus thrombosis
• Tender, red, cone shaped swelling
• heal with scarring
• Recurrences may occur
• Exclude carrier state
• Treatment: Antibiotics
• If large – need incision

14. CARBUNC
LE
• Deep staph. Infection
of several adjacent
hair follicle
• cluster of boils that form
a connected area of
infection
• neck, back, thighs
• In diabetics & debilitated
• Treatment
– Antibiotics,
– Surgical incision

15. Ecthym
a
• By both streptococci
and staphylococci
• Ulcer forms under
a crusted surface
of the infection
• Heals withscarring

16. • Poor hygiene and malnutrition are
predisposing factors
• Minor injuries and other skin
conditions determine the site
• Treatment-
– Improved hygiene and nutrition
– Antibiotics
(phenoxymethylpenicillin and
flucloxacillin)

17. Celluliti
s
• Infection of normal skin flora or
exogenous bacteria
(S. aureus andß-haemolytic
streptococci)
• Deep skin or subcutaneous layer
• Hx of Trauma and Ulceration
• Organisms enter through breach in skin
• Infection can spread to blood
stream Bacteremia /septicemia.

18. Clinical
features
• Acute localised pain
• Oedema
• lymphangitis
&lymphadeniti
s
– Hot painful
erythema streaking,
progressing
proximally from the
affected area,
tracking along
lymphatics
• +/- blister

20. Predisposing
factors
Diabetes
Alcoholism
Malignancy
Drug abuse
venous
stasis
lymphoedem
a

22. Investigation
s
• Swabs taken from relevant sites (from
leading edge or aspirating blisters)
• Gram stain and Blood cultures
• Serological-
– antistreptolysin O titre (ASOT)
– antiDNAse B titre (ADB)

23. Manageme
nt
• Elevate limb.
• Treat underlying
Cause
• Antibiotics
– Phenoxymethylpenicill
in
– erythromycin
– flucloxacillin (all 500
mg qds)
– Vancomycin
• Widespread
– IV antibiotics (3–5 days)
,2
weeks (oral)
• Recurrent
– low dose antibiotic
prophylaxis
(phenoxymethylpenicilli
n)
– Linezolid MRSA
Cellulitis
– Clindamycin

24. Complications-
Local
• Blisters
• Skin necrosis
• Thrombophlebeti
cs
• Lymphadenitis
• Abscesses

25. • Bacteremia
• Septicemia
• Osteomyeliti
s
• Meningitis
Complications-
Systemic

26. Skin
abscess
• Subcutaneous
• localized
collection of pus
• surrounded by
granulation
tissue
• Hx of
– penetrating injury
– infection of
haematoma

27. • S. aureus is the common infecting
organism
• Poor hygiene is predisposing
• Rx- incision and drainage
Features
:
Celluliti
s
Swollen
presen
t
Soft center
feels like
fluid
underneath
Painfu
l
T
ende
r
Celluliti
s
Absce
ss

28. Necrotizing
fasciitis
• Surgical emergency
• Polymicrobial Infection of the fascia
 Type 1- E.coli, Pseudomonas, Proteus,
Bacteroides, Clostridium
Type 2- Streptococcus
• May proceed rapidly to underlying muscle.
• Diagnosis is often delayed
• Primarily a clinical diagnosis
• Rapid progression to septic shock
• Mortality 30-50%

30. Clinical
Features
• Severe pain at the
site of initial
infection
• Tissue necrosis.
• spreading erythema
• pain
• soft tissue crepitus
– (infection tracks
rapidly along the
tissue planes)
• Fever ,Tachycardia

31. Diagnose
on signs
and
symptoms.
Imaging- air
in the
tissues.

32. Clinical findings in necrotising
fasciitis
Early findings
1. Pain
2. Cellulitis
3. Pyrexia
4. Tachycardia
5. Swelling
6. Skin
anesthesia
Late findings
1. Severe pain
2. Skin discoloration (purple
or black)
3. Blistering
4. Hemorrhagic bullae
5. Crepitus
6. Discharge of “dishwater” fluid
7. Severe sepsis or systemic
inflammatory response
syndrome
8. Multi-organ failure

33. • Treat aggressively and
promptly
• antibiotics
–Type 1-
–Broad-spectrum combination
(amoxicillin , imipenem,
levofloxacin)
–Type 2
• benzylpenicillin and clindamycin

34. • urgent surgical
exploration
– Extensive debridement or
– amputation (if necessary)
Necrotizing fasciitis after
debridement

35. ••
Staphylococcal scalded skin
syndrome
exfoliate or
epidermolytic toxin.
• rapidly spreading
tender erythema
• Dermonecrosis
• Outer layer of the
epidermis peel off
• Blistering
• Ritter's Disease of the
Newborn - most severe
form of SSSS

36. • Affects
– infants, immunosuppressed , renal
disease, Malignancy
• Mortality – higher in adult
• Diagnosis
– Clinical
– Culture
– Frozen section examination of skin – shows
split
• Treatment: IV antibiotics & nursing care
or Self limiting.

37. Hidradenitis
suppurativa
• Infection in Apocrine sweat glands
• Common in Axillae and groin and in
females
• Multiple tender swellings
• Enlarging and discharging pus
• Recurrence
• worse in obese individuals
• Rx-
– weight loss
– oral retinoids (Vitamin A)
– Zinc gluconate

38. Erythrasm
a
• Chronic skin infection
of Corynebacterium
• Macular wrinkled, slightly scaly
pink
,brown or macerated white areas
• armpits ,groin or between toe
webs
• Coral pink under Wood’slight
• prevalent among diabetics,
the obese, and in warm
climates
• Rx – Topical fusidic acid

39. Pyomyositi
s
• S. aureus &
Streptococcus infection
of the skeletal muscles
• pus-filled abscess
• most common
in tropical areas- “
myositis tropicans”
• can affect any skeletal
muscle
• most often infects the
large muscle groups
e.g.-quadriceps or

40. • Fever, Sepsis,
Localized
inflammation
• Muscle pain
• Predisposing
factors-
Immunodeficiency,
IVDAs, Trauma
and malnutrition
• Complications-
Abscess, sepsis
• Rx- Drain surgically
and antibiotics

41. Gangren
e
• Clinical situation where extensive tissue
necrosis is complicated by bacterial
infection
Dry
gangrene
Wet
gangrene
Gas
gangrene

42. Dry
Gangre
ne
• The result of
ischaemic
coagulative
necrosis.
• Black, dry,
sharply
demarcated
• Secondary bacterial
infection is
insignificant
E.g. Gangrene of
extremities in
thrombo-embolic

43. Wet
Gangre
ne
• Tissuenecrosisis complicatedby severe
infection.
• Swollen,reddish-black foul smelling
tissue.
• Extensive liquefaction of dead tissue
occurs due to invasion of
organisms & acute inflammation.
• No clear demarcationbetween dead and
viable tissue.
• Occursin extremities and internal organs
E.g.Diabetic gangreneof foot

45. GasGangrene
(Clostridial
myonecrosis)
• Clostridium
perfringen
s
• Extensive
tissu
e destruction
• gas production by
fermentative action of
bacteria.
• Swollenreddish-

46. Treatmen
t
• usually surgical debridement
• amputation (if necessary)
• Antibiotics alone are not
effective