A 10-year-old girl presented with asympto-matic ash colored polycyclic pattern macules of variable size all over the trunk for the last 6 months (Fig. 1). The lesions spread peripherally then became static after a month or so. Skin biopsy from one of the back lesions showed mild basal cell vacoulation, presence of lymphocytes and plasma cells around superficial vascular plexus with prominent melanin incontinence. These findings were consistent with a diagnosis of erythema dyschromiscus.

Ashy dermatosis better known as erythema dyschromicum perstans is an idiopathic derma-tosis characterised by asymptomatic ash colored macules/patches with polycyclic outline. In acute phase the lesion is surrounded by a narrow erythematous rim. The dermatosis commonly involves trunks, arms and face. It occurs predominantly in dark skin over 5 years of age in both sexes with no known internal manifestations. Histopathology in acute phase shows lichenoid dermatitis with basal layer disruption with upper dermis showing peri-vascular infiltrate. Sometimes colloid/civatte bodies as in lichen planus may be present. Thus, some consider it as a variant of lichen planus, namely, lichen planus pigmentosus.

Fig. 1. Ashy dermatosis-Multiple lesions on back

No treatment is effective though cosmetics/camouflage creams can be used. Generally, the pigmentation persists infinitely though spon-taneous disappearance is known to occur.

Sumit Kar*,
Vikram Dutta,
Departments of Dermatology*
and Pediatrics,
Mahatma Gandhi Institute of Medical 
Sciences, Sevagram 442 102, MS, India.