Oral 9, Hypocomplementaemic urticarial vasculitis: a rare but important cause of urticaria and angio-oedema

• Published in: British journal of dermatology (1951) Vol. 156; no. 6; p. 1406
• Main Authors: Roberts, C., Rangaraj, A., Murphy, R.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.06.2007
• ISSN: 0007-0963; 1365-2133
• DOI: 10.1111/j.1365-2133.2007.07876_9.x

A 12‐year‐old girl presented initially with arthritis, back and abdominal pain, weight loss and lethargy. Preliminary blood tests showed a positive antinuclear factor, and low C3 and C4. Serum creatinine was normal but repeat urinalysis demonstrated a persistent proteinuria. A diagnosis of systemic lupus erythematosus was made and immunosuppressive treatment was commenced with hydroxychloroquine and prednisolone orally and methotrexate by intramuscular injection. Initially her joint symptoms slightly improved but after 3 months she was still complaining of lethargy with abdominal pains. She also complained of facial swelling and was noted to have urticaria on her face and limbs. Because of the urticaria and angio‐oedema, low complement levels and abdominal pain, a diagnosis of hypocomplementaemic urticarial vasculitis (HUVS) was considered and serum C1q and C1q antibody titres were determined showing the presence of C1q antibodies and a low C1q titre. A diagnosis of HUVS was made and the immunosuppressive treatment was increased with pulsed methylprednisolone, with improvement of her symptoms. HUVS is a rare condition. Diagnosis depends on the presentation of hypocomplementaemia, urticaria and at least two of the following: vasculitis from dermal biopsies, arthralgia and arthritis, glomerulonephritis, uveitis or episcleritis, recurrent abdominal pain and the presence of C1q precipitating factor in the plasma.1,2 This disorder can present in isolation or in association with other diseases.2 Treatment of HUVS is notoriously difficult and affected individuals are at particular risk of end‐stage renal disease. References 1 Schwartz HR, McDuffie FC, Black LF et al. Hypocomplementemic urticarial vasculitis: association with chronic pulmonary disease. Mayo Clinic Proc 1982; 57:231–8. 2 Walport MJ, Davies KA, Botto M. C1q and systemic lupus erythematosus. Immunobiology 1998; 199:265–85.