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What is Causative agent of Black piedra and explain in detail?
Piedra * Superficial infection of hair shaft where fungal elements adhere to form nodes along hair shaft. Two types: black piedra and white piedra . * Black piedra:- Caused by Piedraia hoae; presents with tiny dark concretions on hairs shafts distributed irregularly; culture shows black velvety colony. * White piedra:- Trichosporon cutaneum (formerly T. beigelii) most common; other species include T. ovoides, T. inkin, and T. asahii); presents with light brown, less adherent nodules coating hair shaft (beard, axilla, pubic hairs). * Of note, T. cutaneum can cause fungemia with systemic disease in immunocompromised patients. Treatment:- shaving/cutting hair, topical imidazoles. Ref:- Sima Jain; pg num:- 226