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, haemoptysis, sinusitis, arthralgia, arthritis, myalgia, abdominal pain, diarrhoea, haematochezia, paraesthesia, weakness, and haematuria may be observed. Can be idiopathic (up to 50% of cases) or secondary to infection, medications (such as antituberculosis medication), collagen vascular diseases, or neoplasms. [from
SNOMEDCT_US]