Cutaneous Manifestations of Small-Vessel Leukocytoclastic Vasculitides in Childhood

In childhood, cutaneous small-vessel vasculitides include Henoch–Schönlein syndrome, a systemic vasculitis, and Finkelstein–Seidlmayer syndrome, a skin-limited vasculitis. Both Henoch–Schönlein and Finkelstein–Seidlmayer syndromes are seen more frequently in white or Asian compared with black children and occur especially in winter and spring with a male-to-female ratio of approximately 2:1. In everyday clinical practice, both conditions are diagnosed on clinical grounds without histological confirmation. The characteristic cutaneous hallmarks of Henoch–Schönlein syndrome include a purpuric rash in all and a subcutaneous edema in approximately every second case, which are often preceded by non-specific red or pink macular elements that mimic a non-itching urticarial rash. Recent data point out that Henoch–Schönlein children often present further cutaneous findings such as Köbnerization, Rumpel–Leede capillary fragility phenomenon, and blistering eruptions. Children with Finkelstein–Seidlmayer syndrome are usually ≤24 months of age and not ill-appearing. They present with (a) large, round, red to purpuric plaques (often with a targetoid appearance) predominantly over the cheeks, ears, and extremities and (b) often tender non-pitting edema of the distal extremities, ears, and face (without pruritus). Both in Henoch–Schönlein syndrome and Finkelstein–Seidlmayer syndrome, there is often scrotal involvement. The cutaneous findings remit without sequelae within 2 months in Henoch–Schönlein and 3 weeks in Finkelstein–Seidlmayer syndrome.