-
Malassezia furfur
- Normal skin flora
- common in individuals who work outside and sweat a lot (hot, humid weather)
- Causes pityriasis or tinea versicolor. Superficial infection of keratinized cells. Degradation of lipids produces acids that damage melanocytes and cause hypopigmented and/or hyperpigmented patches on the chest and back.
- Diagnosis: KOH mount looks like spaghetti and meatball; coppery/orange fluorescence under woods lamp (UV)
- Rx: topical miconazole, selenium sulfide (selsun)
-
Dermatophytes= tinea (ringworms)
Trichophyton
Microsporum
Epidermophyton
- Filamentous fungi (monomorphic) infect only skin and hair or nails
- Trichophyton: infects skin, hair, nails
- Microsporum: infects skin, hair
- Epidermophyton: infects skin, nails
- Itching most common symptom
- if highly inflammatory, generally acquired from animals
- if little inflammatory, generally acquired from humans
- Diseases:
- - Tinea capitis: ringworm of the scalp
- - Tinea barbae: ringworm of the beard
- - Tinea corporis: ringworm of the glabrous skin
- - Tinea cruris: jock itch (groin)
- - Tinea pedis: athlete's foot
- Diagnosis: KOH only hyphae, Microsporum also fluoresces a bright yellow green w/ wood's lamp
-
Sporothrix schenckii
- dimorphic fungus: on plants found as hyphae, in tissues found as Cigar-shaped yeast
- Diseases
- - Sporotrichosis (rose gardener disease): traumatically introduced into the skin, causes local pustule or ulcer with nodules along draining lymphatics (ascending lymphagitis). Little systemic illness
- - Pulmonary sporotrichosis: urban alcoholics, particularly homeless (alcoholic rose garden sleeper disease) is systemic.
- Rx: Itraconazole or potassium iodide
-
Candida albicans
- Forms germ tubes at 37 deg C in serum. Forms pseudo-hyphae and true hyphae when it invades tissues
- Perleche: Crevices of mouth, malnutrition
- Oral thrush, Esophagitis, gastritis, septicemia, endocarditis, cutaneous infections, yeast vaginitis, chronic mucocutaneous candidiasis (CMC): endocrine defects
|
|