[Leukocytoclastic vasculitis]

Leukocytoclastic vasculitis (LcV) is the most common form of cutaneous vasculitis. Often LcV results from deposition of immune complexes in the vascular wall. When IgA is the dominant immunoglobulin in these complexes, systemic involvement is likely (Henoch-Schönlein purpura), being more severe in adults. LcV in which immune complexes are composed of IgG or IgM are more often limited to the skin and may additionally show minor systemic involvement. In other forms of LcV additional pathophysiological factors play a role. LcV can also be a presenting or accompanying symptom of severe systemic ANCA-associated vasculitis. In some cases, LcV is a sign of bacteriemia. The aim of diagnostic procedures is to determine the specific type of vasculitis and degree of systemic involvement as well as possible causes. If no trigger or cause can be found, uncomplicated cases of LcV should be treated symptomatically. Corticosteroids are indicated at initial signs of necrosis or ulceration. Chronic recurrent LcV may respond to dapsone or colchicine. Severe systemic vasculitis requires immunosuppressive therapy.