Inverse Psoriasis

Abstract

Psoriasis is commonly described as a chronic relapsing disease characterized by erythematous well-circumscribed plaques with thick, silvery scale and a predilection for the extensor surfaces of the extremities, lower back, and umbilical area (1-3). Yet the morphology and presentation of cutaneous lesions can vary considerably and can be divided into subtypes, including chronic plaque psoriasis, guttate psoriasis, erythrodermic psoriasis, generalized pustular psoriasis, pustular palmar and plantar psoriasis, and inverse psoriasis (2). Moreover, these subtypes are not mutually exclusive with one type evolving into another over time. Inverse psoriasis is also known as flexural or intertriginous psoriasis because of its selective involvement of skin folds such as the axillae, groin, inframammary folds, navel, and gluteal crease as well as the palms, soles, and nails. Because of its particular localization, inverse psoriasis has clinical impact out of proportion to the total body surface area affected and poses unique therapeutic challenges.