While infectious organisms have been suggested as the cause, microbiologic and virologic analyses cannot pinpoint a single agent.

It is considered an autoinflammatory condition, rather than an autoimmune disease, due to the lack of evidence linking specific antigen-antibody dyads.

A child suspected of having sJIA should undergo a full evaluation for infection and cancer, including blood and urine cultures, imaging tests, and bone marrow exams to rule out leukemia or lymphoma.

The International League of Associations for Rheumatology criteria for sJIA include arthritis, ≥2 weeks of daily fever, and symptoms like organomegaly, lymphadenopathy, serositis, or non-fixed/evanescent rash.

Treatment for a disease varies greatly, requiring consideration of involvement, systemic characteristics, and MAS presence.

Nonsteroidal anti-inflammatory medications can be safely administered for analgesic and antipyretic effects without altering initial diagnostic assessment results.

Studies show that 40% of children with SJIA have a monocyclic disease history, recovering after varying periods.

They often have lost weight and are tired, feverish, experiencing myalgia and arthralgia, as well as occasional chest and stomach pain.

[7] The distinctive fever pattern associated with sJIA is characterized by temperatures that surge above 39 °C once or twice a day and then quickly fall to normal or below baseline.

In one study, 81% of children with active systemic symptoms had abnormal echocardiographic findings, and 36% of patients had an effusion or pericardial thickening.

[6] Roughly one-third of kids with sJIA have occult macrophage activation syndrome (MAS), a potentially fatal illness.

MAS is a condition that causes T cells and macrophages to rapidly multiply and get activated, resulting in a "cytokine storm."

[6] Other causes of fever, such as infections, cancer, and other inflammatory/rheumatologic disorders such autoinflamatory syndromes, systemic lupus erythematosus, and Kawasaki disease, must be ruled out.

This evaluation should include blood and urine cultures, imaging tests, and perhaps a bone marrow exam or lymph node biopsy to rule out leukemia or lymphoma.

[14] According to the most recent International League of Associations for Rheumatology (ILAR) criteria, a child must have arthritis, ≥2 weeks of daily fever that is documented as occurring daily for ≥3 days, and any one of the following symptoms to be classified as having sJIA: organomegaly, lymphadenopathy, serositis, or non-fixed/evanescent rash[29] While there are typical patterns of laboratory abnormalities, such as elevated C-reactive protein levels, high erythrocyte sedimentation rates, neutrophilia, thrombocytosis, and microcytic anemia, there are no particular laboratory tests for sJIA.

Often, nonsteroidal anti-inflammatory medications can be administered safely to offer analgesic and antipyretic effects without changing the results of the first diagnostic assessment.

[14] Clinical trials have shown that anti-interleukin-6 drugs, such as tocilizumab,[30] and anti-interleukin-1 medications, such as anakinra,[31] canakinumab,[32] or rilonacept,[33] are highly successful in managing the disease's systemic symptoms.