Different Patterns of Lichen Planus in Three Members of One Family.

The pathogenesis of Lichen Planus (LP) and its variants, despite many investigative efforts, remains incompletely understood. The occurrence of the disease in siblings suggests a potential role for both genetic and shared environmental factors. Here, three Iranian siblings-one male and two females-who presented with various clinical forms of LP were introduced. Case No. 1 exhibited bilateral facial pigmentation and was diagnosed with Lichen Planus Pigmentosus (LPPigm). Case No. 2 presented with facial pigmentation accompanied by facial papules and was diagnosed with LPPigm and Lichen Planopilaris (LPP). Case No.3 had frontotemporal hairline recession and eyebrow sparsening and was diagnosed with Frontal Fibrosing Alopecia (FFA). Histopathological examination confirmed the diagnoses in all three patients. Patients were treated with an individualized plan that included sunscreen use, potent topical corticosteroids, topical pimecrolimus, minoxidil, and systemic finasteride. To our knowledge, no other family in the literature has been reported to have such a wide range of LP variants. This series underscores the need for further research into genetic and environmental factors contributing to the development of LP and its variants.