Painful rheumatic syndromes associated with human immunodeficiency virus infection.

Severe pain is a prominent characteristic of many rheumatic conditions occurring in patients with human immunodeficiency virus (HIV) infection. These conditions may affect joints or soft tissues. Some painful syndromes, such as acquired immune deficiency syndrome-associated arthritis, may be unique to HIV-infected individuals, whereas others, such as Reiter's syndrome, may also occur in patients without HIV infection but appear more severe in infected patients. Joint and soft tissue pain is usually most intense in the lower extremities. The pathogenesis of the pain is not completely understood but may involve subclinical neuropathic disease.