Juvenile Idiopathic Arthritis Differential Diagnoses

Updated: May 03, 2022
  • Author: David D Sherry, MD; Chief Editor: Lawrence K Jung, MD  more...
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Diagnostic Considerations

Arthritis or arthritis-like symptoms may be present in many conditions. Leukemia is the single most important disease that is mistaken for juvenile idiopathic arthritis (JIA).


Patients with acute lymphocytic leukemia can present with joint pain and arthritis. Expansion of lymphoblasts in bone metaphyses results in pain, which is typically severe and may awaken the child from sleep. Thrombocytopenia is rare in children with JIA; its presence suggests the possibility of leukemia. Lymphocytosis is also uncharacteristic of JIA and likewise raises the possibility of leukemia, particularly when neutropenia is present.

Additional differential diagnoses

Postinfectious arthritis typically affects large joints. This syndrome is clinically indistinguishable from the early phase of JIA, particularly because onset of JIA may be triggered by viral infections; a duration of longer than 6 weeks eventually differentiates JIA.

Acute joint inflammation from JIA needs to be differentiated from septic arthritis, because the 2 disorders may produce a similar clinical picture, with warmth, acute pain, and severely painful range of motion. Although polyarticular symmetrical involvement and distinctive clinical features help to differentiate JIA from pyogenic arthritis, joint aspiration and joint fluid analysis may be indicated.

Thrombocytopenia may be observed in patients with systemic lupus erythematosus (SLE) who present with arthritis, as well as in those with marrow-occupying malignancies (eg, acute lymphocytic leukemia). Thrombocytosis reflects an inflammatory state and often mirrors inflammatory markers in JIA.

Severe joint pain raises the possibility of acute rheumatic fever (also suggested by migratory, but not additive, arthritis with fevers), malignancy with bone marrow–occupying cancers (eg, neuroblastoma, acute lymphocytic leukemia), septic arthritis, and osteomyelitis.

Weight loss without diarrhea is rarely observed in individuals with active JIA but is sometimes associated with anorexia in those with systemic disease. Weight loss is also found in individuals with malignancy, such as acute lymphocytic leukemia or inflammatory bowel disease.

Monoarticular arthritis in a hip is highly unusual in JIA. For isolated hip arthritis, consider Legg-Calvé-Perthes disease, toxic synovitis of the hip, septic arthritis, osteomyelitis, or, in an older child, slipped capital femoral epiphysis or chondrolysis of the hip.

A history of illness in pets and enteritis indicates that the patient might be suffering from reactive arthritis. A history of travel to an endemic area with exposure to ticks suggests the possibility of Lyme disease.

GI symptoms, microcytic anemia, and elevated inflammatory markers raise the possibility of inflammatory bowel disease.

Differential Diagnoses