Chronic musculoskeletal pain in children: part II. Rheumatic causes.

Primary care physicians should have a working knowledge of rheumatic diseases of childhood that manifest primarily as musculoskeletal pain. Children with juvenile rheumatoid arthritis can present with painless joint inflammation and may have normal results on rheumatologic tests. Significant morbidity may result from associated painless uveitis, and children with juvenile rheumatoid arthritis should be screened by an ophthalmologist. The spondyloarthropathies (including juvenile ankylosing spondylitis and reactive arthritis) often cause enthesitis, and patients typically have positive results on a human leukocyte antigen B27 test and negative results on an antinuclear antibody test. Patients with acute rheumatic fever present with migratory arthritis two to three weeks after having untreated group A beta-hemolytic streptococcal pharyngitis. Henoch-Schbnlein purpura may manifest as arthritis before the classic purpuric rash appears. Systemic lupus erythematosus is rare in childhood but may cause significant morbidity and mortality if not treated early. Nonsteroidal anti-inflammatory drugs and physical therapy may be useful early interventions if a rheumatic illness is suspected. Family physicians should refer children when the diagnosis is in question or subspecialty treatment is required. Part I of this series discusses an approach to diagnosis with judicious use of laboratory and radiologic testing.