BIOL 4376 Lecture Notes - Lecture 19: Tinea Corporis, Stratum Corneum, Black Yeast

Cell walls of fungi comprised of carbohydrates, glycoproteins and lipids. Dematiaceous cell walls contain melanin which can be associated with virulence. Superficial infection of the stratum corneum caused by old malassezia. Black piedra is a nodular infection of the hair shaft. White piedra presents with softer, yellowish nodules on the hair. Fungal infections that infect only the keratinized tissue. Unable to grow at 37c which is why the species grows in non-viable skin tissue. Most prevalent fungal infection in the world *this was a quiz question. Infection begins as invasion of nail plate and hyponychium (skin under distal end of nail) Oral treatments (rx only): itraconazole in select patients, terbinafine. Dimorphic fungus exists as a mold outside body, yeast inside body. Introduced into skin by trauma from rose bushes, grasses, trees, sphagnum moss. Can be systemic, typically in lungs and especially in immunocompromised hosts. Avian/bat guano of ohio, missouri and mississippi river; central africa.