and Henoch the purpura and gastrointestinal involvement. The English physician William Heberden (1710–1801) and the dermatologist Robert Willan (1757–1812) had already described the disease in 1802 and 1808, respectively, but the name Heberden–Willan disease has fallen into disuse. William Osler was the first to recognise the underlying allergic mechanism of HSP. See also Cutaneous small-vessel vasculitis References External links Rheumatology Pediatrics Nephrology Autoimmune diseases Ailments of unknown cause Vascular-related cutaneous conditions