Dermographism, Familial

Dermographism is a form of urticaria in which a single stroke or scratch of the skin produces a localized wheal with surrounding red flare. It is the most common form of physical urticaria. Although familial cold urticaria (120100) is well known, the first report of familial dermographism is apparently that by Jedele and Michels (1991). They observed 5 affected individuals in 4 generations with no male-to-male transmission. They illustrated the wheal formation on the skin of the back after a single stroke with moderate pressure.