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

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.