Acute and chronic bacterial infections in rheumatology practice

Abstract

In tropical countries infections are an important cause of morbidity and mortality. Even in tertiary care centers, infections constitute a main cause of morbidity occurring among immunocompetent and immunosuppressed hosts. Here we review the common acute and chronic bacterial infections namely septic arthritis, tropical pyomyositis, tuberculousis, and leprosy-associated arthritis in an immunocompetent host. Septic arthritis presents as acute hot swollen joint and usually occurs in the knee caused by a Staphylococcus aureus infection. Immediate diagnostic tap followed by appropriate antibiotics and drainage results in complete cure. Tropical pyomyositis presents with fever, malaise, and muscle tenderness and/or swelling. Ultrasound will reveal altered echotexture of muscle with or without pus collection. In more than half of the patients multiple muscles are involved. This again is caused by S. aureus in majority of the cases and responds well to antibiotics and drainage. Patients with co-morbidities may have a poor outcome. Chronic monoarthritis involving knee is the most common presentation of tuberculous arthritis however, oligoarticular or polyarticular involvement is not uncommon. Constitutional symptoms or other sites of active tuberculosis are not common. Synovial histology revealing granulomas or mycobacterium bacilli is diagnostic. Leprosy can present with polyarthritis, swollen hands and feet syndrome, erythema nodosum or fever simulating vasculitis, and even lupus. Careful attention to hypoasthetic cutaneous lesions and thickened peripheral nerves may help in clinching the diagnosis of leprosy. Rarely is pure neuritic leprosy associated with arthritis and when present may require a nerve biopsy for diagnosis. Rheumatologists need to be aware of these infections as these are potentially curable.