Location of skin lesions in Henoch-Schönlein purpura and its association with significant renal involvement.

Abstract

Henoch-Schönlein purpura (HSP) is a small vessel IgA-predominant vasculitis. To describe adult patients with HSP and determine if the distribution of skin lesions (ie, purpura above the waist or purpura below the waist only), is a predictor of significant renal involvement at the time of the skin biopsy and the months following. A retrospective study on renal function from 72 adult patients with skin-biopsy proven HSP. Longitudinal renal data were analyzed after HSP diagnosis by using baseline renal function for comparison. Statistical analysis adjusted for sex, age, and baseline creatinine revealed a trend between HSP lesions only on the upper and lower extremities and long-term renal involvement (4.767, P = .067). Moreover, in another analysis adjusted for age and baseline creatinine, lesions located only on the upper and lower extremities significantly increased the odds of having long-term significant renal involvement (6.55, P = .049) in men. This retrospective study used patient information that was subject to selection bias. In patients with HSP, skin lesion distribution on the extremities might be predictive of significant long-term renal involvement and might be critical for risk stratification and development of personalized diagnostics and therapeutics.