A 24 Year Old Male with Hyperpigmented Macules in Face, Neck and Upper Extremities

Abstract

Lichen planus pigmentosus (LPP) is considered to be a macular variant of lichen planus with an unknown etiology. A 24 year old male presented with asymptomatic progressive slate grey to brown-black macules in face, neck and upper extremities. LPP, erythema dyschromicum perstans, reihl’s melanosis, macular amyloidosis and post-inflammatory pigmentation were the common differentials considered. Dermoscopy reveals grey to blue pigment dots forming a net like pattern. Histopathology showed marked pigmentary incontinence, focal basal cell degeneration with minimal perivascular lymphocytic infiltrate in superficial dermis. Based on these findings diagnosis of LPP was made. This rare variant of lichen planus usually affects people with darker skin. It is characterized by slate gray to brown black coloured macules presenting predominantly on the sun-exposed areas, although it can be more widespread. Dermoscopy and histopathology help in confirming the diagnosis. Treatment with vitamin A, oral and topical steroids, topical tacrolimus and photoprotection show variable response.