Papulosquamous annular diseases.

Papulosquamous diseases represent a commonly encountered group of cutaneous disorders in dermatology. Lesions can present with papules and plaques in various configurations, including annular forms. Some of these disorders are expected to appear in annular configurations, such as pityriasis rosea and subcorneal pustular dermatosis. Others may either begin as or even progress to annular configurations, including psoriasis vulgaris, seborrheic dermatitis, and nummular dermatitis. We have reviewed common papulosquamous diseases that can present with annular lesions, which includes psoriasis vulgaris, pityriasis rosea, subcorneal pustular dermatosis, contact dermatitis, seborrheic dermatitis, and nummular dermatitis. For each disorder, we have discussed the details of presentation and differential diseases to be considered.