Erythema Dyschromicum Perstans: Identical to Ashy Dermatosis or Not?

Abstract

Erythema dyschromicum perstans (EDP) and ashy dermatosis (AD) are pigmentary disorders of unknown etiology. EDP is usually considered to be identical to AD; however, a new clinical classification for EDP was proposed in the recent literature. Herein, we report a typical case of EDP observed in an African-American man. Interestingly, the late skin lesions in this case fit the criteria of AD as well. While there appear to be a few clinical cases that can be diagnosed as both EDP and AD based on the clinical course, the preponderance of the evidence in the published reports of EDP and AD and the clinical findings reported here strongly suggest that they are two distinct entities in terms of the extent of the inflammation, albeit on the same spectrum of pigment disorders.

Keywords: Ashy dermatosis; Dermatosis cenicienta; Erythema dyschromicum perstans; Lichenoid tissue reaction; Pigmented skin lesions.

Fig. 1

a Pigmented macules and patches on the back. The skin lesions were arranged in a Christmas-tree pattern. Inset Pigmented macule with an elevated erythematous border. b Pigmented macules and patches on the back after 4 years’ follow-up. Inset Pigmented macules without erythematous halo.

Fig. 2

The biopsy specimens taken from the erythematous border surrounding the pigmented macule on the right thigh revealed hyperkeratosis and parakeratosis in the stratum corneum, and infiltration of mononuclear cells into the epidermis. Partial disruption of the basement membrane as well as melanin incontinence and perivascular lymphocyte infiltration were observed in the dermis. Hematoxylin-eosin. Original magnification ×40.