Arthropathy and HIV infection. A muddle of mimicry.

Several rheumatic diseases are associated with human immunodeficiency virus (HIV) infection. The most common are reactive and psoriatic arthritis. Classic septic arthritis caused by Staphylococcus aureus and other common organisms is very rare: Instead, infectious arthritis caused by unusual organisms is the rule. Some of the HIV-related rheumatic syndromes behave like classic rheumatic diseases, while others may actually be new forms of disease. Often, one of the rheumatic syndromes is the presenting manifestation of underlying HIV infection. HIV-infected patients and patients with rheumatic disease often have similar laboratory abnormalities. Systemic lupus erythematosus, in particular, may be mistaken for HIV infection, in part because of cross-reactivity of antibodies. However, coexistence of systemic lupus erythematosus and rheumatoid arthritis with HIV infection is a rare occurrence. Traditional therapy for rheumatic diseases may not be indicated in HIV-infected patients and in fact may even be contraindicated.