The scalp is the most common place for people with psoriasis to get a rash. Some people will have only a small area affected, especially on the back of the head or upper neck, while other people may develop a rash covering the entire scalp.
Appearance of Scalp PsoriasisThe borders of the rash are well-defined and can advance down the neck or in front of the ears. The scales are often very thick and white and they can be tightly attached to the hair. Scalp psoriasis does not usually cause hair loss but the hair is often thinner in the areas involved because there is more shedding in the telogen phase.
Confused with Seborrheic DermatitisScalp psoriasis and seborrheic dermatitis are often confused. Even biopsied sections of scalp can look similar. In general, the patches of scalp psoriasis are more well-defined than those of seborrheic dermatitis. In cases where it is difficult to determine the difference, some doctors call the rash "seborrhiasis."
Habif, Thomas. "Psoriasis." Clinical Dermatology, 4th Edition. Ed. Thomas Habif, MD. New York: Mosby, 2004. 209-39.
Papp, K., et al. "Scalp psoriasis: a review of current topical treatment options." Journal of the European Academy of Dermatology and Venerology 21(2007): 1151-60.
van de Kerkhof, Peter. "Psoriasis." Dermatology. Ed. Jean Bolognia. New York: Mosby, 2003: 531-5. 125-37