Hypocomplementemic Urticarial Vasculitis (HUVS) with Precocious Emphysema Responsive to Azathioprine

Abstract

Hypocomplementemic urticarial vasculitis syndrome (HUVS) is an uncommon small-vessel vasculitis first described by McDuffie and colleagues in 1973 [1]. Diagnostic criteria proposed by the same authors include two major criteria (urticaria lasting more than 6 months, hypocomplementemia) plus two minor criteria (leukocytoclastic vasculitis, arthralgia or arthritis, uveitis or episcleritis, glomerulonephritis, recurrent abdominal pain, positive C1 q precipitin test result) [2]. Other clinical manifestations of HUVS may include angioedema, central nervous system involvement and obstructive lung disease [2–4]. Women are more frequent affected by HUVS mainly in the fourth decade of life [3, 4]. The presence of anti-C1q precipitins directed against the collagen-like region of C1q is an hallmark of this syndrome. The role of these antibodies is unknown, although their presence has been associated with a greater frequency of obstructive lung disease. Indeed, about 50 % percent of patients with HUVS have chronic obstructive pulmonary disease (COPD) [2, 4]. Pulmonary emphysema may be clinically significant within a few years of the diagnosis of HUVS [5, 6]. However, to our knowledge, this complication has never been described in childhood and adolescence. HUVS etiology remains unclear and most of the presentations are idiopathic, although some cases have been reported associated with infections, malignancies, drugs and connective tissue diseases such as systemic lupus erythematosus (SLE) and Sjogren’s syndrome [4]. No specific therapy is currently available for HUVS [3, 4].