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.