White piedra can be treated by using topical antifungals, including imidazoles,
ciclopirox olamine, 2% selenium sulfide, 6% precipitated sulfur in petroleum, chlorhexidine solution, Castellani paint, zinc pyrithione, and amphotericin B lotion.
ref:http://www.emedicine.com/DERM/topic614.htm
ref:http://nahrsmembers.org/home/PatientInformationFAQs/HairShaftDefectsFAQ/tabid/68/ItemId/36/Default.aspx
ref:http://www.emedicine.com/DERM/topic788.