cutaneous leukocytoclastic angiitis
Cutaneous leukocytoclastic angiitis is a small-vessel vasculitis presenting with palpable purpura and urticarial lesions which predate the purpuric lesions most frequently observed on the legs. Systemic symptoms including fever, cough, hemoptysis, sinusitis, arthralgia, arthritis, myalgia, abdominal pain, diarrhea, hematochezia, paresthesia, weakness, and hematuria may be observed. Skin biopsy reveals exudates rich in neutrophils, endothelial damage, fibrin deposition, and leukocytoclasis in postcapillary venules of small vessels. Cutaneous leukocytoclastic angiitis can be idiopathic (in up to 50% of cases) or secondary to infections, medications (such as antituberculosis medication), collagen vascular diseases, or neoplasms.