Severe leukocytoclastic vasculitis with necrotic ulceration of the lower limbs mimicking cellulitis

Leukocytoclastic vasculitis (LCV) is a common form of small vessel vasculitis (also known as hypersensitivity vasculitis or cutaneous necrotising vasculitis) characterised by the histopathological finding of neutrophilic debris in and around blood vessels. It is idiopathic in around half of cases but may be secondary to infection, underlying malignancy or drug reactions. The cutaneous features of LCV include palpable purpura, urticarial plaques, bullae and necrosis; systemic involvement may affect the joints, kidneys and gastrointestinal tract. Henoch-Schönlein purpura (HSP) is a well-known immunoglobulin A-mediated subtype of LCV that preferentially affects children.