Purpose: To evaluate the clinical features and outcome of patients with isolated hypersensitivity vasculitis (HV).
Patients and methods: Retrospective study of patients with cutaneous vasculitis followed up at a University Hospital from 1975 to 1994. Patients with vasculitis secondary to collagen vascular diseases, neoplasia, or major infections were excluded. Patients were classified as HV according to the differential criteria proposed by Michel et al (J Rheumatol. 1992;19:721-728).
Results: Ninety-five patients were classified as HV. The mean age was 42.7 +/- 21.7 years, with similar disease frequency in both sexes. In 43 patients, the precipitating event was drug therapy, either alone or as a treatment for a coexistent infection, usually an upper respiratory tract infection. The most frequent clinical manifestation was palpable purpura followed by joint symptoms. Systemic involvement was infrequent: 7 patients had nephropathy, manifested almost exclusively by microhematuria, and 5 patients had gastrointestinal symptoms. In 54 subjects the vasculitis did not require treatment; 26 patients were treated with NSAIDs, and 14 required corticosteroids (associated to immunosuppressive agents in 2 of them). After a mean follow-up of 15.5 +/- 28.9 months (median 6), only 2 patients had slight renal impairment, whereas the remaining had a complete recovery.
Conclusion: Hypersensitivity vasculitis is usually a benign syndrome, often secondary to drugs or infections, or both. Its main clinical manifestations are skin and joint symptoms. The systemic involvement is scarce and its prognosis is excellent.