Dandruff: A mild skin condition that produces white flakes that may be shed and fall from the hair.
Dandruff is due to the sebaceous glands overworking. (The sebaceous glands keep the skin properly oiled.)
Another cause of dandruff is fungus, especially one called Pitrosporum ovale. (Most people have this fungus, but people with dandruff have more.)
For dandruff, there are several tiers of treatment:
The active ingredients approved for dandruff treatment by the U.S. Food and Drug Administration (FDA) include tar, pyrithione zinc, salicylic acid, selenium sulfide, sulfur, and ketoconazole.
Ketoconazole, once only available by prescription, was approved in 1997 by the FDA for over-the-counter (OTC) sale in the form of Nizoral A-D shampoo. This medication can be helpful for particularly difficult cases, according to some pharmacists.