White piedra (trichosporosis).

White piedra, caused by the yeast-like fungus Trichosporon cutaneum , is a superficial infection involving hair. The causative organism is easily isolated on Sabouraud's medium. Simple clinical and mycological techniques employed in making a positive identification are outlined. The organism rapidly colonizes hair when suspended in normal saline. To our knowledge, these are the fourth and fifth cases of white piedra reported in the United States. The incidence is probably greater than appreciated, for most lesions are just visible to the naked eye and, without close scrutiny, may be easily overlooked.