Non-thyphoidal salmonellosis in patients with systemic lupus erythematosus. A study of fifty patients and a review of the literature.

The objective of this study was to characterize the clinical profile of lupus patients with non-typhoidal salmonellosis. A retrospective review of the clinical charts of lupus patients diagnosed with bacteriologically proven non-typhoidal salmonellosis over the last 20 y was undertaken, paying special attention to risk factors, clinical presentation and treatment outcome. Most episodes were bacteraemic without a localizing focus; and some patients were afebrile. They usually occurred in patients prone to opportunistic infections, and at times of increased immunosuppression given for lupus flares (especially nephritis). However, salmonellosis also occurred in some patients presenting with lupus. The C-reactive protein level was found to be significantly higher during the infective episodes compared to episodes of non-infective febrile lupus flare. All isolates were sensitive to the usual first-line antibiotics and eminently treatable with 3 weeks of appropriate antibiotics without recurrence/persistence or significant morbidity/mortality, the exceptions being spinal osteomyelitis and septic arthritis involving deformed joints requiring surgical debridement and prolonged antibiotic therapy for eradication. Mortality occurred in the setting of septic shock from mixed-microbial sepsis and major organ failure from active lupus. There is a high association of non-epidemic, non-typhoidal salmonellosis with SLE, especially in patients with active disease on intensified immunosuppression. The C-reactive protein value may be helpful in distinguishing between fever from a pure lupus flare and one complicated by infection.