Fungal infections Flashcards
Cutaneous mycosis
Tinae versicolor: by malassezia furfur: degradation of lipids produces acids that damages melanocytes and cause hypopigmented and hyperpigmented patches. Occurs in hot, humid weather
Treat with topical miconazole, selenium sulfide (selsun), Sphagetthi and meatball appearance on KOH prep
Other tinae: includes tinae pedis (foot), tinae cruris (groin), tinea corporis (ringworm, on body), tinae capitis (head, scalp), tinae unguinum (onychomycosis, on fingernails).
Pruritis lesions with central clearing resemling a ring, caused by dermatophytes (microsporum, trichophyton, epidermophyton). See mold hyphae in KOH prep, not dimorphic.
Candida albicans
Dimorphic: pseuhyphae and budding yeast at 20C, gram tubes at 37C
Treat: topical azole for vaginal, fluconazole/caspofungin for oral/esophageal, fluconazole/ampho/caspofungin for systemic
Aspergilus
Invasive, esp in immunocmp and CGD
Allergic bronchopulmonary aspergilisL ABPA, with astham or CF
Aspergillomas in lung cavities, especially after TB
Some produce aflatoxin, associated wtih HCC
Septae hyphae at 45’ angle. Conidiophore with radiating chains of spores
Crypto
Encapsulated, NOT dimorphic, soil and pigeon dropping.
Laxtax agglutination tests polysaccharide apsular antigen and more specific.
Soap bubble lesion in brain.
Mucor and rhizopus app
Mucormycosis
Mostly in ketoacidtoci and diabetic and leukemic patient
Fungi proliferate in blood vessel walls when there is excess ketone and glucose.
Penetrate cribiform plate and enter brain
Rhinocerebral, frontal lobe abscess: headache, facial pain, black necrotic eschar on face. May have CN involvement.
Pneumo jirovecii
Cuases PCP, a diffuse interstitial pneumo
Yeast. Diffuse bilatreal. Disc-shaped yeast form on methanamine silver stain of long tissue
Tx: TMP-SMX, pentamidine, dapsone, start prophylaxis when CD4 <200
Sporothrix schenskii
Sporotrichosis
Dimorphic, cigar shaped budding yeast that lives on vegetation.
When spores traumatically introduce in the skin by a thorn (rose gardner’s disease), causes local pustule or ulcer when nodules along draining lymphatics (ascending lymphangitis). Little systemic disease
Treatment: itraconazole or POTassium iodide
Plant a rose in the POT
