Salmonella septic arthritis in systemic lupus erythematosus and other systemic diseases.

Salmonella infection is an important problem in immunocompromised patients. The synovium is a particular metastatic focus of Salmonella infection and can result in many disabilities of life. Systemic lupus erythematosus (SLE) patients were highly susceptible to Salmonella infection. In the past 6 years, 41 patients with Salmonella septic arthritis have been treated in our hospital. Eleven patients had an underlying systemic disease of SLE which presented with a distinctive clinical course. Alcoholic liver disease (six cases) was another common underlying systemic disease. The most frequent predisposing articular factor was avascular necrosis (16 cases). The hip joint was the most commonly involved site. Salmonella group B was the most common serotype (30/41). Seventy-three per cent (8/11) of the SLE group had involvement of two or more joints compared with only three out of 30 patients in the non-SLE group. The sex differentiation shows a predominance of young females (10/11) in the SLE group and middle-aged males in the non-SLE group. Moreover, in the SLE group, all 11 patients shared the risk of lupus nephritis and steroid use. Ten patients had Salmonella group B bacteraemia and five had urinary tract infections simultaneously. In the non-SLE group, there were 10 patients with a history of steroid use, three with antecedent enteritis, 12 with bacteraemia, and three with necrotising fasciitis. Seven patients in each of the groups had a recurrent course. However, three patients in the non-SLE group had died during the episode of septic arthritis.