[Septic arthritis in connective tissue diseases and other chronic arthropathies]

In order to describe the features of septic arthritis (SA) in patients with connective tissue diseases (CTDs), a series of 17 CTD cases with SA episodes were studied retrospectively. The most common CTDs were systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Involvement was oligoarticular in 64% of cases and mono-articular in the remainder. Clinical, radiological and laboratory findings proved insufficient to allow differential diagnosis between SA and an underlying arthritic flare-up, which could only be carried out by bacterial isolation from synovial fluid. The most frequent etiological agent was Staphylococcus aureus (Table 1). Throughout, patients were treated by needle drainage together with antibiotics, first by parenteral (average 17 days) and later by oral route (average 46 days). Cases with greater diagnostic delay and initiation of therapy were those requiring arthrotomy and those who presented more complications mainly osteomyelitis and permanent disability (Table 2).