Ashy dermatosis (Q89742)

Ashy dermatosis is an asymptomatic disorder of skin pigmentation of disputed aetiology characterised by widespread persistent and often symmetrical pale slate-blue macules in healthy individuals. It shares both clinical and histological features with lichen planus but mucous membranes are unaffected. Preceding erythema around the margins of the pigmented macules may be noted in a minority of patients, in which case the disorder may be referred to as erythema dyschromicum perstans. It has been described principally from Central and South America and from Asia.