1. Medical Mycology: Superficial, Cutaneous and Subcutaneous Mycoses
Hugh B. Fackrell

2. Mycoses & Mytoxicosis Mycoses: fungal infections
Mytoxicosis: intoxicaton

3. Fungal Disease Mycoses Colonization of the host
Mycotoxicosis: Intoxication
Hypersensitivity

4. Fungal Entry Rarely cause disease in healthy person Commensal
Candida albicans
Malasseza fufur
Underlying disorder
trauma
immunological deficiency
debilitating conditions

5. Disease Mechanisms of Fungi
Exogenous
Opportunistic
inhalation
Superficial
Trauma hygiene
Cutaneous
trauma
Subcutaneous
Systemic
Endogenous
Opportunistic
Iatrogenic
(physician induced)
e.g. indwelling lines catheters

6. Fungal Dissemination Breach in host defenses Must repair defect
endocrinopathies
immune disorders
iatrogenic
Must repair defect

7. Host Defense Factors Intact skin long chain fatty acids pH
Bacterial antagonism
corneum stratum desiccated
epithelial cell turnover rate (0.5 kg/yr.)
Mucous membranes
ciliated
antimicrobials
Immunological competence

8. Fungal Infections Superficial fungal infections Cutaneous Mycoses
Opportunistic Infections
Superficial fungal infections
Cutaneous Mycoses
Subcutaneous Mycoses
Systemic Mycoses

9. Structure of Skin

10. Superficial Fungal Infections
Skin Infections
limited to Stratum corneum
do not penetrate deeper tissues
No inflammation

11. Superficial mycoses Pityriasis versicolor Black piedra White piedra
tinea nigra

12. Black Piedra Superficial mycosis Piedraia hortai
small firm black nodule
Surrounds hair shaft

13. White Piedra Superficial mycosis Trichasporon beigelii
soft friable beige nodule
distal ends of hair shaft

14. Pityriasis Versicolor
Common superficial mycosis
Superficial keratin layer
hypo or hyper pigmentation on skin of neck shoulders chest and back
Malassezia furfur

15. Malassezia furfur

16. Tinea Nigra Superficial mycosis Phaeoannellomyces werneckii
silver nitrate type of stain
palm of hand

17. Cutaneous Mycoses
Dermatophytoses
Dermatomycoses

18. Dermatophytoses Cutaneous Mycoses
Secrete keratinolytic enzymes which dissolve the skin protein KERATIN
Three genera
Epidermophyton.
Microsporum,
Trichophyton
Anatomic specificity correlates with genus
-skin,hair,nails.

19. Epidermophyton

20. Microsporum

21. Spores on outside of hair follicle
Microsporum
Ectothrix
Spores on outside of hair follicle

22. Microsporum

23. Microsporum

24. Microsporum
Spores of Microsporum lie outside the hair shaft. This is known as ECTOTHRIX
Can be seen with an ultra violet lamp called a “Woods” light. Bright fluorescence.
Children are more susceptible than adults, because post pubertal sebum has fungistatic fatty acids especially M.audouinii

25. Microsporum audouinii,canis
M.audouinii -Predominant species in temperate climates.
Very contagious can cause epidemics
Spread by barbers tools, seat head rests
M.canis- Second most common- spread by kittens, pups - young animals

26. Trichophyton

27. Trichophyton

28. Trichophyton

29. Trichophyton

30. Dermtaophytes: Tinea Infections
Tinea capitis Head, scalp, neck
Tinea barba Face
Tinea corporis Body
Tinea.cruri Groin, perineum
Tinea pedis Feet
Tinea unguium -Nails
TINEA means RINGWORM

31. Tinea capitis
Ringworm of the scalp-very contagious- especially pre-pubertal children.
Begins with small, itchy, scaling papule
spreads peripherally makes a roundish lesion,
Hair breaks off at scalp level, leaving a patch.

32. Tinea Capitis

34. Tinea corporis
Ringworm of the body,with annular lesions the centre is scaly and the periphery advancing circle of vesicles and papules.
Prefers areas that are hairy soon to become bare due to the fungus.
Associated with poor nutrition and hygiene but is also common in persons who frequent gymnasiums and pools.

36. Tinea pedis
Tinea pedis - “Athletes foot”skin cracks between toes, maceration of tissue,desquamation, ulcerations, can spread whole bottom foot.
Epidermophyton and Trychophyton. ~ 2% carry fungus no symptoms.men susceptible

37. Tinea Pedis

39. Tinea cruris
T.cruris- Groin, perineum,perianal region Epidermophyton floccosum or inguinale. Tight pants,perspiration,pubic contact.
Epidermophyton and Trychophyton. ~ 2% carry fungus no symptoms.men susceptible

40. Tinea Cruris
Epidermophyton

41. Tinea unguium Nails brittle thick,discoloured, grooved.
Trichophyton rubrum most common in women aged 40-50
Persistent very difficult to treat. Antibiotics cannot be effective.

43. Dermatomycoses Cutaneous fungal infections inflammation
caused by opportunistic fungi
Candida spp

44. Cutaneous Mycoses: Treatment
Mild cases topical treatment
3% sulfur+3% salicylic acid ointment
1% crystal violet
1% iodine
1% tolnaftate
10% undecylenic acid
miconazole haloprogin

45. Cutaneous Mycoses Treatment
Serious or stubborn cases
Griseofulvin - 1gram /day for 1-3 months
This antimicrobial extracted from cultures of Penicillium griseofulvum in 1939 not used as a drug until 1959

46. Subcutaneous Mycoses
Caused by trauma [puncture]and introduction of the fungus and bacteria.
Chromoblasomycosis
Phaeohypomycosis
Mycetoma
Sporotrichosis

47. Chromoblastomycosis Subcutaneous mycosis verrucoid skin lesions
lower extremities
Histology
muriform cells- cross walls in two directions
no involement of bone tendon or muscle

50. Phaeohypomycosis Infections caused by dermatiaceous fungi
hyphal to yeast forms in tissue
Dermatiaecous Fungi
melanin black fungi

51. Mycetoma Granulomatous local lesions Suppuration
usually of the legs and feet
infect humans who have extensive contact with soil and foliage due to bare feet and legs.
Suppuration
small visible pigmented grains or granules
microcolonies
Destroys bone tendon and muscle

52. Mycetoma Madura foot caused by many organisms Eumycotic mycetoma
fungal
USA Pseudallescheria boydii
Actinomycotic mycetoma
bacterial
USA Nocardia brailiensis
Madura foot

53. Sporotrichosis world wide-Sporothrix schenkii
ulcerative lesions at site on injured skin usually arm, spread to the regional lymph nodes. The high risk group, gardeners, farmers who work with wood/ soil.
Highly infectious on contaminated dressings to patients with wounds.

54. Sporotrichosis

55. Sporotrichosis

56. Sporotrichosis

57. Treatment of sporotrichosis
topical potassium iodide
amphotericin B systemically.