Diagnosis: Lichen planus
Watercolour drawing of the arm of a man showing an unusual form of lichen planus. Includes sketch detail of papules on the skin. Keywords: Godart, Thomas. Clinical photograph sourced from Wikimedia Commons (CC BY 4.0). Attribution: Godart, Thomas.
Flat-topped, violaceous, polygonal papules with fine white lines on surface (Wickham striae). Predilection: flexor wrists, ankles, lower back, oral mucosa. Oral LP: lacy white reticular pattern (Wickham striae), erosive form is painful. Koebner phenomenon present.
Peak incidence 30-60 years. May be triggered by hepatitis C (check HCV serology), medications (ACE inhibitors, thiazides, antimalarials), dental amalgam. Oral erosive LP carries small risk of malignant transformation to SCC.
Cutaneous: potent topical corticosteroids, calcineurin inhibitors, phototherapy (NB-UVB). Oral: topical corticosteroids (fluocinonide gel), calcineurin inhibitors, systemic corticosteroids for severe erosive disease. Nail: intralesional triamcinolone.
Drug eruption (lichenoid), Psoriasis, Lichen simplex chronicus, Secondary syphilis, Pityriasis rosea
Always check hepatitis C serology. Wickham striae are pathognomonic. Oral erosive LP requires long-term follow-up for malignant transformation. Cutaneous LP is usually self-limited (1-2 years) but oral LP often chronic.
Tags: lichen planus, inflammatory, mucocutaneous, papulosquamous