Solitary and multiple epidermolytic acanthoma: A demographic and clinical study of 131 cases

Epidermolytic acanthoma (EA) is a rare, benign acquired cutaneous keratosis displaying epidermolytic hyperkeratosis in more than 50% of its surface. Because of the sparsity of comprehensive studies, little is known on the patient demographics and clinical characteristics of this uncommon entity. We wish to comprehensively characterize the clinical and demographic features of EA and to differentiate it from its mimickers.

We carried out a retrospective review of 131 cases of EA, recorded clinical and histopathologic features and performed linear regression of yearly incidence rates to assess for possible under-reporting of this entity.

EA affected both genders equally. We found 9.08 cases per 100 000 biopsy specimens per year and linear regression analysis showed significantly decreasing incidence rates. Analysis of the anatomical site distribution of EA lesions showed a more frequent genital location in men (39.1% of cases in men, as compared to 11.3% for women). Contrary to previous studies, lesions were most frequently single (91.7%) and the mean age of presentation was 57.8 years.

The presented largest case series to-date indicates that EA is probably an underdiagnosed entity and establishes the demographic and clinical features of EA.