"The Science Behind Winter Dry Scalp and How a $12 Hair Serum Can Help"
Originally Published 2 years ago — by USA TODAY

Dandruff is often mistaken for a dry scalp, but it's actually a manifestation of the skin condition seborrheic dermatitis caused by an inflammatory reaction to yeast. Triggers for flare-ups include going long periods between shampoos, and the frequency of washing hair to prevent dandruff varies by person. Using antifungal shampoos and shampooing as often as possible can help reduce yeast build-up and lead to a more dandruff-free head of hair.