Pathogenesis: uncertain
Epidemiologic features:
(1) typically occurs in Caucasians
(2) typically occur in adults, rarely seen in children
(3) some cases have been familial
Clinical findings:
(1) skin infarcts (termed "drops of porcelain" with an erythematous rim). This often start as crops of small papules on the trunk, arms and legs with sparing of face, palms, soles and scalp.
(2) gastrointestinal infarcts with abdominal pain and bowel perforations
(3) cerebral infarcts
(4) ocular infarcts (conjunctiva, retina, other)
(5) infarcts in other organs (lung, heart, kidney, lung, pancreas, etc.)
A skin biopsy shows wedge-shaped zone of dermal necrosis beneath an atrophic epidermis. At the tip of the wedge there are small arterioles and/or deep venules showing lymphocytic vasculitis, fibrinoid necrosis, thrombosis, endothelial swelling and other changes. Mucin may be located in the dermis between collagen bands.
Laboratory findings:
(1) Some patients show increased platelet aggregation.
(2) Some patients have shown decreased fibrinolytic activity.
(3) Some patients demonstrate antibodies to arterial antigens.
Diagnosis often requires exclusion of other conditions (allergic necrotizing vasculitis, systemic lupus erythematosus, atrophie blanche, other causes of lymphocytic vasculitis).
The prognosis is often poor when there is a systemic disease involving multiple organs. A patient with involvement limited to the skin may have prolonged survival.
