# Lichen Planus Initially Presenting as Poikiloderma: A Challenging Case Report

## TL;DR

A 33-year-old woman presented with a long-term skin condition initially resembling a rare disease, but was later diagnosed with lichen planus, highlighting the importance of recognizing unusual symptoms.

## Contribution

This case report adds to the understanding of lichen planus by documenting an atypical initial presentation resembling poikiloderma.

## Key findings

- The patient's initial poikilodermatous changes were later confirmed as lichen planus after extensive testing.
- The case emphasizes the need for thorough diagnostic evaluation to distinguish LP from similar conditions like mycosis fungoides.

## Abstract

Lichen planus (LP) is a chronic inflammatory disorder that affects the skin, mucous membranes, nails, and hair. Cutaneous LP (CLP) is characterized by violaceous, polygonal, flat-topped papules and plaques that are intensely pruritic. Although it can develop on any part of the body, it most commonly affects the flexor surfaces of the wrists, lower back, and ankles. This report presents an atypical case of LP in a 33-year-old woman who initially exhibited poikilodermatous changes with bluish-gray patches, persisting for a decade. Due to the overlapping clinical and histopathological features, an extensive diagnostic workup including pan-computed tomography, lymph node biopsy, and immunohistochemistry was performed to exclude poikilodermatous mycosis fungoides. One year later, skin examination and histopathological evaluation revealed the classical features of LP, leading to a definitive diagnosis. This case highlights an unusual presentation in which poikiloderma preceded the classic clinical picture of LP. Our findings contribute to the existing knowledge of LP by emphasizing the importance of recognizing atypical presentations for accurate diagnosis and management.