Panniculitis: another clinical expression of gout

Gouty panniculitis is an unusual clinical manifestation of gout, characterized by the deposition of monosodium urate crystals in the lobular hypodermis. Its pathogenesis is poorly understood but is associated with hyperuricemia, and the clinical presence of indurate subcutaneous plaques, which may precede or appear subsequently to the articular clinical expression of tophaceous gout. The aim of this report is to describe the clinical characteristics and potential risk factors for the development of lobular panniculitis secondary to chronic tophaceous gout. This is a retrospective clinical review of 6 patients with gouty panniculitis seen at the rheumatology service at the National University of Colombia. All cases fulfill diagnostic criteria for gout. The presenting clinical characteristics of each case were analyzed. All 6 patients were men, with an average age of 26 years. Two patients initially presented with cutaneous manifestations, and in the remainder 4 joint involvements preceded the cutaneous manifestations. Articular involvement first developed in lower extremities, of intermittent nature, and subsequent occurrence of polyarthritis of upper and lower extremities. A positive family history of gout was observed in half of the patients. Smoking and high alcohol intake were relevant risk factors. On physical examination, all exhibited the presence of erythematous, irregular surface, deep indurate subcutaneous plaques. Biopsy of skin and deep dermis including panniculus revealed the presence of granulomatous inflammatory changes with deposition of amorphous eosinophilic material surrounded by palisading histocytes and lymphocytes. Characteristic negative birefringent monosodium urate crystals were observed in the synovial fluid of patients with arthritis. All patients exhibited high levels of serum uric acid and were non-complaint to treatment with allopurinol, NSAIDs, and colchicine. Gouty panniculitis should be considered in the differential diagnosis of panniculitis, especially in the presence of high levels of uric acid. It is usually observed in the third decade of life and may appear prior to the inflammatory articular manifestations of tophaceous gout.