Clinical analysis of 48 cases of inverse psoriasis: a hospital-based study.

Inverse psoriasis, rare in clinical practice, refers to psoriasis only or mainly occurring at flexural sites, such as the axilla, antecubital fossae, popliteal fossae, and inguinal creases. It is also known as flexural psoriasis. With a total collection of psoriatic cases from September 2002 to December 2003 at Xijing hospital, we made a retrospective analysis of the disease history, clinical characteristics, and treatment of the patients affected with inverse psoriasis. The results showed that the major clinical manifestations of inverse psoriasis were sharply demarcated erythematous plaques with varying degrees of infiltration and minimal or no scales. Affected areas often involve the groin, axilla, genitals, and umbilicus. The disease responds well to the narrow band UVB therapy. Compared with common psoriasis, inverse psoriasis has similar and unique characteristics in terms of the affected areas, clinical symptoms, and responses to the treatment.