Cutaneous involvement by leukocytoclastic vasculitis can be seen in a wide range of conditions.
The patient may present with palpable purpura.
A punch biopsy of skin shows a neutrophilic vasculitis of dermal capillaries, venules and arterioles. Fibrinoid necrosis and leukocytoclasis (fragmented neutrophilic nuclei) may be present. Immunofluorescence may show immune complex deposition.
Causes of leukocytoclastic vasculitis include:
(1) bacterial, fungal or viral infection
(2) drugs
(3) autoimmune disorder (hypersensitivity vasculitis, Crohn's disease, SLE, RA, ulcerative colitis, etc)
(4) COVID-19 vaccination
(5) cancer in distant organ (with immune response)
(6) idiopathic
The vasculitis is often limited to the skin but can be systemic. Other sites affected by the vasculits include:
(1) gastrointestinal tract
(2) kidneys
(3) joints
