[Hypocomplementemic urticarial vasculitis].

BACKGROUND Low-complement urticarial vasculitis is an uncommon condition associating urticaria, glomerulonephritis, obstructive ventilatory disorders, and anti-Ciq antibodies. CASE REPORT We report a case in a 34-year-old woman who developed urticaria with purpura, membranoproliferative glomerulonephritis (creatinine 238 mumol/l) and bronchial obstruction with bronchectasia. Total complement and the C3 fraction were low. Anti-C1q antibodies were found in the serum and anti-DNA antibodies were negative. Aggravation of the respiratory and renal failure progressed despite corticosteroid therapy, leading to death at 4 months. DISCUSSION Bronchial obstruction in low-complement urticarial vasculitis results from emphysema and is often life-threatening. Our case exhibited an unusual feature due to the lack of radiodetectable emphysema, the presence of bronchectasia and the rapid degradation of the respiratory function.