Diseases sometimes associated with psoriasis. II. Alopecia areata.

Of 5,033 patients examined between 1968 and 1975, 407 were diagnosed as having psoriasis (Ps) and 23 alopecia areata (Aa). Five of the 23 patients with Aa had also Ps. One Aa patient having pitting of the nail only was not included in the Ps group. One further patient with Aa himself not affected with Ps had a sibling with Ps. It is suggested that there is an association between Ps and Aa and that the pitting of the nails described in Aa may be in reality an expression of Ps.