Skin Fungi

Question 1

Malassezia Furfur

Answer 1

• dimophic yeast
• short mold form on skin spaghetti and meatballs

Human (teenager). direct/indirect contact ith infected person. tropical/subtropical

Pityriasis Vesicolor (tinea versicolor). superficial skin infection of stratum corneum lesions are irregular macules of hypo/hyperpigmentation(interferes with melanin production). may be covered with fine scale, minimal itching, cosmeticly impotant. no inflammation.

Dg. skin scrappings for yeast and short mold from chest upper back, arms or abdomen

TX. spontanoues healing. ketoconazole, othre azoles, topical seleium sulfate

Question 2

Tinea Nigra

Answer 2

unfection stratum corneum, due to septate fungi, black/brown pigment due to melanin production.

black maculae on skin mostly of the palm

Question 3

Black piedra and white piedra

Answer 3

hair infction, nodular growth, as clumps on hair shaft, mold septate fungi.

Question 4

Dermatophytes groups

Answer 4

monomorphic mold septate hyphae. macroconidia and microconidia spores.

Soil, animals, anthropophilic (human). direct/indirect contact spores or hyphae. hot/humid climate

TX. topical and oral antifungals

Question 5

Sporothrix Schenckii

Answer 5

• dimophic mold septate hyphae with condida in rosettes
• yeast oval elongated cigar shape

Soil, vegetation, thorns. Florist/Gardener

lymphocutaneous sporotrichosis “rose grower disease”

1. primary lesion: chronic nodular ulcerative
2. Secondary lesion: linear chain of painless subcutaneous nodules along the draining lymphatics. lesions may ulcerate and discharge pus.

Dx. culture at 25 and 35/7oC

Tx. oral potasium iodide or itraconazole

dd. mycobaterium ..???

Question 6

Chromomycosis

Answer 6

pigmented molds

soil, woody plants (phialophora, cladosporium) tropical/rural. enter thru trauma.

slow progressive granulomaous infection. tough warty growth. highly destructive by not systemic infeciton

Question 7

Eumycotic Mycetoma

Answer 7

spp include petriellium, madurella. tropic area with low raifal. enter thru trauma

localize, chronic granulomatous, multiple granuloma and abcesses that contain large aggregates of fungal hyphae “granules or grains”

deep draining sinuses with pus

extension to muscle, fascia, bone (destructive)

Question 8

Candida Albicans

Answer 8

Opportunistic fungi

yeast, reprodcued by budding, long germ tube, pseudohyphae (elongtated yeast). thick walled chlamydoconidia

normal body flora in skin, mouth, rectum, vagani, of many animals. moist, warm, diabetes, weak immune systems. endogenous. ph, sugar increase, decreased normal flora after antibiotic use.

cutaneous candidiasis. folliculitis, erythema, vissicles (diaper rash)

mucocutaneous. whittish pseudomembranous lesions composed of epithelial cells, yeast, and pseudohyphae. oral thrush, esophagua, intestine and vaginal.

systemic candidiasis. bronchi, lung, GI, septicemia, endocarditis, meningitis.

Dgx: swab, wet mount and gram stain demonstrate budding yeast. germ tube tes enocualte animal serum at 37oC for 90 min . grow in agar culture round small colonies.

TX. imidazoles (topical or oral), nystatin, amphotericin B for systemic disease