hypocomplementemic urticarial vasculitis
Hypocomplementemic urticarial vasculitis (HUV) is an immune complex-mediated small vessel vasculitis characterized by urticaria and hypocomplementemia (low C1q with or without low C3 and C4), and usually associated with circulating anti-C1q autoantibodies. Arthritis, pulmonary disease, ocular inflammation, and glomerulonephritis are common systemic manifestations.