Fungal Infections in Papules, Plaques

Question 1

Candida albicans

Answer 1

Fungal Infections in Papules, Plaques
• *dimorphic fungus
• ubiquitous- air, water, soil
• normal microbiota skin, mouth, GI, GU
• opportunist
VIRULENCE
- *adhesins,
- *proteinases
- *phospholipases,
- biofilms,
- *dimorphic
DIAGNOSTIC
• direct microscopic examination most rapid and cost effective
o *fluorescent calcofluor white
• *Sabouraud dextrose agar (SDA) 1-2 weeks
- *Germ tube test
DISEASES
Cutaneous candidiasis
• skin, nails, mucous membranes (thrush, vaginitis)
• usually limited to *stratum corneum
• Common lesion is *plaque, *satellite lesions are common
• moist skin areas E.g. groin, obesity folds, toe webs
Candida intertrigo
- superficial skin disorder involving any area of the body where opposing skin surfaces may touch and rub
• *inflammation of skin folds
• *erythematous, *macerated plaques and erosions
– often *pruritic, may be *painful
Candida onychomycosis
• usually *fingernails
• cosmetic to physical discomfort→→ ↑risk *secondary bacterial infect. (e.g. *cellulitis)

Question 2

Sporothrix schenckii

Answer 2

Fungal Infections in Papules, Plaques
• *dimorphic fungus
   o *septate hyphae *"flower arrangement)
   - *clusters of ovoid conida
- *cigar shaped yeast
• soil, plants
- grows on SDA
- causes *lymphocutaneous sporotrichosis
...”rose-gardener’s disease”
o traumatic introduction-->granulomatous nodule-->lymphatic nodule-->ulcerate & pus