The clinical presentation of intensely pruritic, violaceous, polygonal papules on flexural surfaces (often described as the '6 P's': pruritic, purple, polygonal, planar papules and plaques) is classic for lichen planus. The presence of white, lacy lesions on the buccal mucosa, known as Wickham's striae, further confirms the diagnosis of oral lichen planus, which frequently coexists with cutaneous lichen planus. Psoriasis typically presents with erythematous, scaly plaques; pityriasis rosea with a herald patch followed by smaller oval lesions in a 'Christmas tree' pattern; and atopic dermatitis with eczematous, pruritic lesions, often in flexural areas but lacking the violaceous, polygonal morphology.
Sign up free to access AI-powered MCQ practice with detailed explanations and adaptive learning.