Actinic Lichen planus: A Photodistributed dermatosis in an outdoor worker

Abstract

Actinic lichen planus is a rare photodistributed variant of lichen planus that predominantly affects sun-exposed skin, especially in individuals with darker skin phototypes living in tropical and subtropical regions. Ultraviolet radiation is considered an important precipitating factor, and lesions often present as asymptomatic or mildly symptomatic annular, hyperpigmented, violaceous, or dyschromic plaques over the face and other exposed sites. We report a 42-year-old male outdoor worker who presented with progressively enlarging dark lesions over the face for five months. Cutaneous examination revealed multiple well-defined annular plaques over the bilateral cheeks and forehead with a violaceous to hyperpigmented center surrounded by a striking hypopigmented rim. Dermoscopy showed a diffuse brown background, multiple gray-brown dots and globules, fine reticular white lines corresponding to Wickham striae, and peripheral hypopigmentation. Histopathological examination demonstrated epidermal atrophy, basal cell vacuolar degeneration, a dense band-like lymphocytic infiltrate at the dermoepidermal junction, and pigment incontinence with numerous dermal melanophages, confirming actinic lichen planus. The patient was started on broad-spectrum sunscreen and a mid-potency topical corticosteroid with advice regarding strict photoprotection. This case highlights the characteristic clinicodermoscopic and histopathological profile of actinic lichen planus and emphasizes the need to consider this uncommon entity in the differential diagnosis of chronic photodistributed facial pigmentation.