HYPOPIGMENTED MACULES IN ACANTHOLYTIC DISORDERS

Background. Widespread hypopigmented macules are rarely seen in heavil y pigmented patients with Darier's disease. Previous hypotheses concer ning the cause of decreased pigmentation suggest it is a postinflammat ory phenomenon or that the hypomelanosis is evidence of subclinical ac antholysis. Patients. This report presents 2 patients: a new case of d isseminated guttate leukoderma in a black patient with Darier's diseas e and the first such case in a patient with transient acantholytic der matosis (Grover's disease). Direct immunofluorescence and electron-mic roscopic studies were carried out on lesional biopsies. Observations. Numerous small hypopigmented macules were observed in two black patien ts followed for acantholytic disorders. Three biopsies of the hypopigm ented macules revealed acantholysis, while one showed only decreased m elanin. Direct immunofluorescence studies were negative. Electron-micr oscopic studies of the leukodermic macules showed sparse melanocytes a nd melanosomes that were mostly pigmented stage IV melanosomes. Conclu sions. Disseminated guttate leukoderma can occur in transient acanthol ytic dermatosis, as well as in Darier's disease. It is readily apparen t on darkly pigmented skin because of contrast. The etiology of this p henomenon is still unknown.