A REFRACTORY CASE OF HYPOCOMPLEMENTEMIC URTICARIAL VASCULITIS

Abstract

<h3>Introduction</h3> Hypocomplementemic Urticarial Vasculitis (HUV) is a rare small vessel vasculitis. Patients present to allergy clinic with recurrent urticarial lesions. Proposed diagnostic criteria include 2 major criteria: recurrent urticarial lesions and hypocomplementemia, with at least 2 minor criteria: dermal biopsy showing leukocytoclastic vasculitis, arthralgias/arthritis, organ involvement, or elevated anti-C1q antibodies. We describe here the clinical presentation and therapeutic management of a refractory case of HUV. <h3>Case Description</h3> A 28-year-old female presented with a 2-year history of inflammatory arthritis and recurrent hives. Workup revealed hypocomplementemia: C3: 60, C4:10, decreased serum C1q<3.6, elevated anti-C1q antibody (102) and negative autoimmune markers. Cutaneous biopsy showed IgG/C3 at the basement membrane. She had been diagnosed with HUV and treated without benefit with different medications regimens including prednisone, hydroxychloroquine, colchicine, and dapsone all discontinued due to adverse effects/ineffectiveness. Patient was then tried on Methotrexate and Cyclosporine with limited benefit and later on Mycophenolate and omalizumab with minimal improvement. Over time, she developed pulmonary capillaritis, pericarditis, and episcleritis. She progressively developed a multi-organ, complex syndrome all of which was attributed to HUVS. After multiple failed therapies and poor control of urticaria multi-disciplinary decision was made to start Rituximab. <h3>Discussion</h3> Suspicion of HUVS should increase when hives do not respond to therapy, last>24 hours, and leave hyperpigmentation upon resolution. Differential diagnosis includes Muckle-Wells syndrome (hearing loss), Cogan syndrome (progressive hearing/vision loss), Sharp syndrome (positive U1-RNP antibodies), and SLE (positive ANA, normal levels of C1 esterase inhibitor). The case describes an aggressive form of HUV and highlights refractory disease with escalating therapies.