Abnormalities were found by immunofluorescence in five of 11 (45%) patients with transient acantholytic dermatosis. There was no consistent pattern to the abnormalities; for example, they were circulating antibodies to intercellular and basal cell antigens in two persons and to basement zone antigens in a third. Deposits of Ig and/or C3 were present in lesions of three patients and C3 was present in the intercellular substance in the lesions of a fourth patient. These findings suggest that different immune mechanisms may be involved in the pathogenesis of transient acantholytic dermatosis.Transient acantholytic dermatosis is a papular eruption of the skin characterized by numerous small, pruritic, erythematous papules and papulovesicles.(1)The lesions are most common on the trunk and, whether treated or not, last for months to years. One of the striking features of the disease is the presence of acantholytic cells within the epidermis.(2)This histological finding is reminiscent of the superficial and deep forms of pemphigus and raises the possibility that transient acantholytic dermatosis could also be associated with immunologic abnormalities.To study this possibility, we performed immunofluorescence studies in patients with transient acantholytic dermatosis.