Current Trends in Trichosporon-Related Mycoses in Traslacional Era

White stone is a superficial mycosis caused by fungi of the genus Trichosporon spp., and is characterized by the formation of whitish or yellowish nodules firmly attached to the hair shaft. The infection primarily affects the scalp, although it may also appear in the beard, mustache, eyebrows, axillary region, and genital area. The condition is usually asymptomatic; however, mild pruritus or irritation may occur in some cases. White piedra is more prevalent in tropical and temperate regions with high humidity, with Brazil reporting the highest number of documented cases. In Mexico, reported cases remain limited and are mainly concentrated in the states of Tabasco and Chiapas.

The main risk factors associated with this infection include long and persistently moist hair, inadequate hygiene, warm climates, the use of head coverings or veils, hyperhidrosis, immunosuppression, and tying the hair when it is still wet. Trichosporon species are widely distributed in nature and may transiently colonize the human microbiota. The species most frequently implicated in white piedra are T. inkin, T. cutaneum, T. ovoides, and T. loubieri. These microorganisms exhibit several pathogenic mechanisms, including the production of lytic enzymes such as proteases, lipases, and hemolysins, and the ability to alter their morphology depending on environmental conditions.

Diagnosis is typically established through direct microscopy, which reveals whitish or cream-colored colonies. However, precise species identification requires molecular techniques, particularly sequencing of the IGS1 region, which provides greater discriminatory power than the ITS region.