Superficial Fungal Infections

1. Superficial Fungal
Infections
Dr.T.V.Rao MD
11/23/2012 Dr.T.V.Rao MD 1

2. SUPERFICIAL MYCOSES
The superficial mycoses are usually
confined to the outermost layer of skin,
hair and do not invade living tissues.
11/23/2012 Dr.T.V.Rao MD 2

3. SUPERFICIAL MYCOSES
Pityriasis
versicolor
Tinea nigra
Black piedra
White
piedra
Keratomycosis
11/23/2012 Dr.T.V.Rao MD 3

4. 11/23/2012 Dr.T.V.Rao MD 4

5. PITYRIASIS VERSICOLOR
(Tinea versicolor)
• Superficial chronic infection of
Stratum corneum
• Etio: Malassezia furfur
(Pityrosporum orbiculare)
(Lipophilic yeast)
• Clinical findings: Hyperpigmented
or depigmented maculae on chest,
back, arms, abdomen
11/23/2012 Dr.T.V.Rao MD 5

6. Superficial
• Do not elicit
immune
response
• No discomfort
• Cosmetic
problems
• Limited to
stratum conium
11/23/2012 Dr.T.V.Rao MD 6

7. Pityrisis versicolor
11/23/2012 Dr.T.V.Rao MD 7

8. Ring worm Infections
• Infection of the Stratum corium.
• Called as Dermatophytosis or
Tinea.
• Called as per the site of Infection.
• Tinea pedis – feet are involved.
• Tinea captis – Scalp.
11/23/2012 Dr.T.V.Rao MD 8

9. RING WORM LESIONS
11/23/2012 Dr.T.V.Rao MD 9

10. Tinea lesions on Scalp
11/23/2012 Dr.T.V.Rao MD 10

11. Ring worm lesions on Face
11/23/2012 Dr.T.V.Rao MD 11

12. Severe nail infection with Trichophyton rubrum in
a 37-year-old male AIDS patient.
Source: Intern. J. Dr.T.V.Rao MD 31(1992): 453.
11/23/2012 Dermatol. 12

13. Dermatophytes,
• There are 20 species of Dermatophytes
infect humans.
• Classed under broad category.
1 Trichophyton,
2 Microsporum,
3 Epidermophyton
Infective particles -, a fragment of keratin,
11/23/2012 Dr.T.V.Rao MD 13

14. Common spp of Dermatophytes
Infecting Humans
• T.rubrum
• T.mentagrophytes
• T.tonsurans
• T.verucosom
• Epidermophyton floccosum
• Microsporum cannis
11/23/2012 Dr.T.V.Rao MD 14

15. Identification of Genus
• Identified on the Basis of Macro
conidia.
• Identification of species depends on
the disposition of Microcondia
• Majority of Dermatophytes produce
1 Macro conidia and 2 Micro
conidia.
In Epidermophyton Micro conidia are
absent
11/23/2012 Dr.T.V.Rao MD 15

16. FUNGAL DISEASES
. Cutaneous mycoses: Fungal infections of the skin,
hair, and nails.
 Secrete keratinase, an enzyme that degrades keratin.
 Infection is transmitted by direct contact or contact
with infected hair (hair salon) or cells (nail files,
shower floors).
 Examples:
– Ringworm (Tinea capitis and T. corporis)
– Athlete’s foot (Tinea pedis)
– Jock itch (Tinea cruris)
11/23/2012 Dr.T.V.Rao MD 16

17. Cutaneous mycoses
involves
• Skin
• Hair
• Nails
• Evoke cellular immune
response
• Dermatophytes
• Clinical manifestations
ringworm or tinea
11/23/2012 Dr.T.V.Rao MD 17

18. Cutaneous mycoses
Etiology
• Microsporum
Trichophyton
Epidermophyton
11/23/2012 Dr.T.V.Rao MD 18

19. Cutaneous mycoses
• Classifications:
Anatomic location
Tinea pedis Tinea capitis
Tinea corporis
Tinea cruris
Ecologic location
Geophilic
Zoophilic
Anthrophilic
11/23/2012 Dr.T.V.Rao MD 19

20. Basic types of
Dermatophytic infection:
1. The acute or inflammatory type of
infection, which is associated with CMI to
the fungus, generally heals spontaneously
or responds nicely to treatment.
2. The chronic or non-inflammatory types
of infection, which is associated with a
failure to express CMI to the fungus at the
site of infection, is relapsing and responds
poorly to treatment.
11/23/2012 Dr.T.V.Rao MD 20

21. Classification of Dermatophytes
• Trichophyton
• Microsporoum
• Epidermophyton
Differentiated on the Basis of
Macrocondia,By Microscopy
11/23/2012 Dr.T.V.Rao MD 21

22. Cutaneous Mycosis
11/23/2012 Dr.T.V.Rao MD 22

23. Macroconida
11/23/2012 Dr.T.V.Rao MD 23

24. Macroconida
11/23/2012 Dr.T.V.Rao MD 24

25. Micro conidia
11/23/2012 Dr.T.V.Rao MD 25

26. Spread of Dermatophytes,
• Spread of infection occurs through direct or indirect
contact.
• Other ways of spread,
From – Floors of swimming pools.
Brushes,Combs,Towels,
Predisposing factors
Peeling of skin or minor trauma
Genetic predisposition ?
T Cell immunity is important,
Phagocytes play a role.
Invade Keratin ,Enzymatic, or Mechanical causes.
11/23/2012 Dr.T.V.Rao MD 26

27. Trichophyton
• Colonies are powdery ,velvety,
• Micro conidia are abundant,
• Arranged in clusters,
• Hyphae are borne on conidiophores
• Special hyphal structures.
• Infects
Skin, Hair, Nails,
11/23/2012 Dr.T.V.Rao MD 27

28. Microsporum
• Colonies are cotton like,
• Velvety or powdery,
• Macroconida are scanty,
• Macrocode are large ,Multicellular spindle
shaped,
• Infects
Hair, and Skin,
Nails are not infected.
11/23/2012 Dr.T.V.Rao MD 28

29. Epidermophyton
• Colonies are powdery
, greenish yellow,
• Macroconida are
multicellular, pear
shaped, typically
arranged in clusters.
• Infects - Skin, Nails
But not Hair.
11/23/2012 Dr.T.V.Rao MD 29

30. General characteristics of Macroconida
and Microconidia of Dermatophytes
Genus Macroconidia Microconidia
Microsporum Numerous, thick Rare
walled,rough
Epidermophyton Numerous, smooth Absent
walled
Trichophyton Rare,thin walled, Abundant
smooth
11/23/2012 Dr.T.V.Rao MD 30

31. Macroconida
11/23/2012 Dr.T.V.Rao MD 31

32. Pathogenesis
• Depends on – site – species,
• Only dry scaling
• Hyperkeratosis,
• Irritation, Erythema of skin,
• Weeping pustules,
• Ulceration,
11/23/2012 Dr.T.V.Rao MD 32

33. Clinical Presentation
• Can produce Lesions on Body,face,scalp
• Annular lesions ,raised,inflamatory
borders,
• Groin lesions spread outwards from flexor
areas,
• Toe clefts, sole
• Nails get discolored, thickening, and
become friable.
11/23/2012 Dr.T.V.Rao MD 33

34. On scalp
• Scaling Hair loss,
• Hyphal break up to chains.
• Endothrix –T.tonsurans,T.violaceum
• Ectothrix - Microsporum,T.verucosum.
• In Endothrix breaks at the mouth of follicle,
Black dot,
• In Ectothrix breaks hair 2-3 mm from mouth of
the follicle.
• Mixed infections do occur.
11/23/2012 Dr.T.V.Rao MD 34

35. The Hair may show
Endothrix or Exothrix
11/23/2012 Dr.T.V.Rao MD 35

36. Cutaneous mycoses
• THE IDENTIFICATION REACTION(ID)
• Patients infected with a dermatophytes may
show a lesion, often on the hands, from which
no fungi can be recovered or demonstrated.
• It is believed that these lesions, which often
occur on the dominant hand (i.e. right-handed or
left-handed), are secondary to immunological
sensitization to a primary (and often unnoticed)
infection located somewhere else (e.g. feet).
• These secondary lesions will not respond to
topical treatment but will resolve if the primary
infection is successfully treated.
11/23/2012 Dr.T.V.Rao MD 36

37. Clinical Manifestations
• Appear as scaly
lesion
• Upper trunk, neck
• May be Hypo
pigmented and
Hyper pigmented
• Spread to other
sites of the body
11/23/2012 Dr.T.V.Rao MD 37

38. Laboratory Diagnosis
• Direct
Microscopy,
• Demonstration of
clusters of round
yeast cells
• Short and stout
hyphae,
11/23/2012 Dr.T.V.Rao MD 38

39. Id reaction
• Inflammation
associated with
infection with
fungi
• An
immunological
reaction to fungal
infection
11/23/2012 Dr.T.V.Rao MD 39

40. Laboratory Diagnosis
• Collection of samples,
• Specimens of skin, hair, nails
• Collected in folded black paper,
• Stored up to 12 months,
• Nails by clippings,
• Skin by scrapping with blunt scalpel,
• Hair by plucking
11/23/2012 Dr.T.V.Rao MD 40

41. Microscopy,
• Direct Microscopy with wet mount
preparation with 15-20%
Potassium hydroxide (Koh)
preparation
• Examination under fluorescent
Microscope with Calcoflour
• Examination under Woods lamp
11/23/2012 Dr.T.V.Rao MD 41

42. Examination under Wood’
Lamp
11/23/2012 Dr.T.V.Rao MD 42

43. Culturing of
Dermatophytes
• Small fragments of Keratinous material
used for culturing on
• Sabouraud's agar,
• 4 % Malt extract agar,
• Colony morphology and color
pigmentation observed.
• Microscopic observation
11/23/2012 Dr.T.V.Rao MD 43

44. Treatment and Prevention,
• Topical therapy
• Application of
Topical Azoles
,compound
Terbinafin,oral
Grisofulvin,
11/23/2012 Dr.T.V.Rao MD 44

45. Treatment
• Pityriasis responds to Topical
therapy,
• 1% Seliniumsulphide,
• Azoles – Ketoconazole.
• Oral Azoles,
11/23/2012 Dr.T.V.Rao MD 45

46. Treatment
• Skin – azoles,inhibits cytochrome
450 dependent enzyme systems
at the demethylation step from
lanosterol to ergosterol
• Hair- Griseofulvin, oral , affects
micro tubular system
11/23/2012 Dr.T.V.Rao MD 46

47. Other Fungal Infections of Skin
• Pityriasis Versicolor ,Belong to Genus
Malassezia
• Infection of stratum corneum
• Manifest as patches of discoloration of
skin,
• Caused by lipophilic yeast
• Depends on Host and Environments,
• Tropical countries- Young adults,
11/23/2012 Dr.T.V.Rao MD 47

48. Morphology
• Produce
round yeast
cells,
• Short hyphae
• Appear as
Gram Positive
11/23/2012 Dr.T.V.Rao MD 48

49. Candidiasis can Present as Skin
Lesions
• Candidiasis ,
Monoliasis,
• Can infect Skin,
Mucosa, or
Internal Organs,,
• Called as Yeast
Like fungus
11/23/2012 Dr.T.V.Rao MD 49

50. Candida and other species,
• Candida albicans,
• Others spp
C.tropicalis,
C.Krusei,
C.glabrata,
C.parapsilosis,
11/23/2012 Dr.T.V.Rao MD 50

51. Candida
• Common flora
Exist in Mouth, Gastrointestinal tract.
Vagina, skin in 20 % of normal
Individuals.
Colonization increases with age, in pregnancy
Hospitalization
Immunity Depends on T lymphocytes, and
Europhiles
11/23/2012 Dr.T.V.Rao MD 51

52. Morphology and Culturing
• Ovoid shape or spherical budding cells
and produces pseudo mycelium
• Routine cultures are done Sabroud’s
Glucose agar,
• Grow predominantly in yeast phase
• A mixture of yeast cells and pseudo
mycelium and true mycelium are seen in
Vivo and Nutritionally poor media.
11/23/2012 Dr.T.V.Rao MD 52

53. Pseudohypal structures in
Candida
11/23/2012 Dr.T.V.Rao MD 53

54. Pathogenesis and Pathology
• Mucosal infection superficially –Discrete white
patches on mucosal surface.
• Can affect tongue
• Infants and old persons are affected
• Immune compromised /AIDS. Oral Candidiasis
is commonly seen
• Vaginal Candidiasis causes itching soreness
white discharge, White colored lesions,
• Pregnancy with advance,
• One episode through life time
11/23/2012 Dr.T.V.Rao MD 54

55. Other lesions
• Esophageal infection common in HIV /
AIDS
• Skin – Nail infections
• Axilla Groin
• Toe clefts,
• Napkin dermatitis,
• Nails frequent immersion in water
House wives, Washer man Nurses,
11/23/2012 Dr.T.V.Rao MD 55

56. Predisposing factors.
• Infancy, old age,
Pregnancy,
• Change of flora.
• Moisture, occlusion
Trauma
• T Lymphocyte
disease. Neutropenia.
• Diabetes mellitus
11/23/2012 Dr.T.V.Rao MD 56

57. Location of Infections
• Localized and
Disseminated.
• Multi organ
involvement.
• Kidney,Liver,Splee
n, Brain.GIT.Eye,
• Catheter related
infections,
11/23/2012 Dr.T.V.Rao MD 57

58. Other lesions
• Chronic muco
coetaneous
Candidiasis
• In childhood –
suspect defects
of Lymphocytes
and Neutrophils,
11/23/2012 Dr.T.V.Rao MD 58

59. Laboratory Diagnosis
• Skin scrapings,
• Mucosal scrapping,
• Vaginal secretion
• Culturing Blood and other body fluids,
• Observations
Microscopic observation after Gram
staining. Gram + yeast cells.
11/23/2012 Dr.T.V.Rao MD 59

60. Cutaneous mycoses
• Laboratory diagnosis: scrapings from
clinical specimens
• Hair – endothrix (spores inside the hair
shaft -ectothrix
-exception: T.schoenleinii
Disease-favus-waxy mass of hyphal
elements (scutulum) microscopic –
degenerated hyphal elements
11/23/2012 Dr.T.V.Rao MD 60

61. Cutaneous mycoses
• Cultures
• Selective media – containing
Cyclohexamide and
chlorampenicolincubate at 25 C.
• Identification based on the
conidia
11/23/2012 Dr.T.V.Rao MD 61

62. Diagnosis
• Diagnosis is based upon:
1. Anatomical site infected
2. Type of lesion
3. Examination with a Woods lamp (366
A°)
4. Examination of KOH-treated skin
scales from the infected area
5. Culture of the organism (not too
important)
11/23/2012 Dr.T.V.Rao MD 62

63. Diagnosis of Deep seated
infections
• Difficult to
culture,
• Alternative
methods
• Antibody titers,
• ELISA testing
• CIE
11/23/2012 Dr.T.V.Rao MD 63

64. Culturing
• Sabouraud's Medium or Blood agar
• Yeast colonies appear within 1-2 days
• Germ tube test - Incubation of colonies in
serum at 37 c from 1.5 to 2 hours produce
• Short hyphae known as germ tube
• Candida albicans are Germ tube
producers
• Other tests are – Sugar assimilation and
fermentation tests.
11/23/2012 Dr.T.V.Rao MD 64

65. Germ Tube Test
C.albicans
11/23/2012 Dr.T.V.Rao MD 65

66. Germ Tube Test
C.albicans
11/23/2012 Dr.T.V.Rao MD 66

67. Treatment
• Skin
removal of the organism by:
1.Selenium sulfide
2.Thiosulfate
3.Salicylic acid
4.Hyposulfite
inhibition of ergosterol by:
1.miconazole
11/23/2012 Dr.T.V.Rao MD 67

68. Treatment with Modern Drugs
• Nystatin,
• Amphotericin B
• Miconazole,
• Topical Imidazole application
• Systemic infection needs
Intravenous – Amphotericin B
Intravenous or Fluconazole.
11/23/2012 Dr.T.V.Rao MD 68

69. Differential diagnosis
• In a differential diagnosis you must consider:
1. Leprosy
2. Secondary syphilis
3. Pityriasis rosea
4. Psoriasis
5. Nummular eczema
6. Lichen planus
7. Alopecia areata
8. Trichotillomania
9. Dyshidrosis
10. Contact dermatitis.
11/23/2012 Dr.T.V.Rao MD 69

70. Programme Created by Dr.T.V.Rao MD
for Medical and Paramedical Students in
Developing World.
Email
doctortvrao@gmail.com
11/23/2012 Dr.T.V.Rao MD 70