Volume 21 Number September 2015 Case presentation Lichen planus pigmentosus in linear and zosteriform pattern along the lines of Blaschko

Relhan Vineet, Sethi Sumit, Vijay, Nita Khurana, Md, Sethi Senior
Lichen planus pigmentosus (LPP) is a variant of lichen planus (LP) reported in various ethnic groups. It occurs predominantly in the third or fourth decade of life and is characterized by the insidious onset of dark-brown macules in sun exposed areas and flexural folds. Rarely, has it been described in a linear or segmental distribution. Herein we describe a case of LPP with lesions lateralized to right side of body along the lines of Blaschko, in a linear and zosteriform pattern. Case synopsis
more » ... A 48-year-old man presented to us with asymptomatic patches of hyper-pigmentation on the body for 1 year. The pigmentation initially appeared on the volar aspect of his right forearm and gradually these lesions increased in number to involve the right arm, chest, and right lower limb in a discontinuous distribution. The pigmentation was confined to the right side of body and and progressed to its present extent over a period of two months with no change in number or color ever since. At no time during the clinical evolution was the rash palpable. There was no history of any drug intake, topical application, significant sun exposure, or trauma prior to eruption. The patient never had herpes zoster and family history was not contributory. Hematological and biochemical investigations were within normal limits. Serology for hepatitis B and C virus was negative. On cutaneous examination, uniformly pigmented dark brown-black macules were present in a linear non-contiguous pattern on flexural surfaces of the right forearm and arm and in a zosteriform pattern on the right chest wall. Multiple linear swirls involved the right buttock, thigh, and leg (Figure 1, 2). These macules were 0.2-2 cm in size, irregular in shape, and well circumscribed. His face, mucous membranes, scalp, and nails were spared. Histopathology examination of a hyperpigmented macule on the forearm revealed an unremarkable epidermis, pigment incontinence and melanophages, and scanty perivascular lymphocytic infiltrate in the upper dermis, thus compatible with the diagnosis of LPP (Figure 3). He was started on topical tacrolimus 0.1% to be applied twice daily.