White piedra is a relatively uncommon superficial fungal infection of the terminal hair shaft. It is caused by environmental, skin-colonizing fungi from the genus Trichosporon. Different species of Trichosporon preferentially affect different hair-bearing areas of the body, with Trichosporon inkin being more likely to infect pubic hair and Trichosporon ovoides more commonly infecting hair of the scalp. Co-infection with Corynebacterium species has been reported.

White piedra presents as soft, white, creamy white, or light brown nodular concretions along the terminal hair shaft. These concretions are distributed in an irregular manner and may coalesce to form tubular structures. They can be easily separated from the hair shaft. The infection is chronic and typically asymptomatic, though it does have the potential to cause hair breakage. The most common sites affected by white piedra are pubic, axillary, and facial hair, while the hair of the scalp is rarely involved. A variant presentation of white piedra of the scalp appears more like tinea capitis, with hyperkeratosis and alopecia with or without concretions along the hair shaft.

Patients affected by white piedra may be of any age, sex, and ethnicity. It is found in temperate and semitropical climates, including much of South America, Africa, Europe, the Middle East, Southeast Asia, India, and Japan. It has historically occurred infrequently in the United States, though there have been an increasing number of documented cases, including in the Northeastern and Southeastern United States.

Important risk factors for developing white piedra are living in an endemic area, humidity, poor personal hygiene, and hyperhidrosis. Spread through person-to-person contact is uncommon.

Immunocompromised Patient Considerations:
Immunocompromised patients can develop severe life-threatening sepsis from disseminated fungal infection from Trichosporon species. Cutaneous signs of dissemination include widespread purpuric papules and nodules with associated necrosis. This is seen most commonly in patients with neutropenia (including patients with hematologic malignancy and those undergoing chemotherapy), though it has been documented with other causes of immunosuppression, including AIDS. The vast majority of reported cases do not reference preceding white piedra.