The pressure-dependent nature of the rash in Henoch Schönlein purpura.

Abstract

A 10 month old girl with Henoch-Schönlein purpura (HSP) developed a rash predominantly on the anterior aspect of the knees. The authors speculate that this distribution of the rash was due to the pressure effects consequent to crawling and propose that the distribution of the rash in HSP should be described as pressure-dependent rather than merely gravity-dependent. The therapeutic implications of pressure-dependency in HSP are discussed.