Condition		Clinical findings	Physical examination findings	Associated findings
Acute rheumatic fever or streptococcal infection–related arthritis		Migratory arthritis two to three weeks after streptococcal pharyngitis;, age of onset usually school age, with distribution proportionate to risk for streptococcal infection	Characteristic rash; carditis is a serious complication; chorea is a late finding and can occur years after the illness.	Evidence of antecedent streptococcal infection (see Table 3)
		Persistent arthritis may indicate streptococcal infection–related arthritis.
Benign hypermobility syndrome		Intermittent pains at night; age of onset usually three to 10 years, more common in girls	Evidence of hypermobility (i.e., hyperextended metacarpophalangeal joints, elbows, or knees)	Must rule out other disorders (e.g., Marfan syndrome, Ehlers-Danlos syndrome, Down syndrome); positive family history common
Benign nocturnal limb pains of childhood (“growing pains”)		Cramping lower-leg pain in the evenings or nights; age of onset is three to 10 years	Normal during and after episode	Laboratory tests and radiography usually unnecessary; results generally normal
Henoch-Schönlein purpura		Rash, abdominal pain, often triggered by upper respiratory tract infection; age of onset typically school age, median is four years.	Purpuric rash, nonspecific swelling	Hematuria and proteinuria if renal involvement; check for hypertension; urinalysis at least monthly for six months to evaluate for renal involvement
Juvenile rheumatoid arthritis		Three subtypes distinguished by the number of affected joints: Pauciarticular: Limp with nonpainful joint swelling involving four or fewer joints; age of onset usually younger than eight years Polyarticular: Joint swelling involving five or more joints, diminished use; bimodal age distribution, one to six and 11 to 16 years Systemic-onset: Daily fevers with high spikes, recurring evanescent erythematous rash, variable joint involvement, hepatosplenomegaly, generalized lymphadenopathy; age of onset varies	Swelling/synovitis, rash, constitutional symptoms; uveitis usually insidious and found only on routine eye screening, although patients may present with pain, redness, photophobia, or visual changes	Laboratory testing not helpful: rheumatoid factor, ANA, and ESR results may be normal; CBC may be abnormal in systemic disease.
Juvenile rheumatoid arthritis				An elevated ESR is worrisome for other diagnoses, such as malignancy² or infection.
Malignancy (osteosarcoma, rhabdo-myosarcoma, leukemia, lymphoma)		Painful joints, bone pain, constitutional symptoms; no age predominance because clinical presentations vary	Ill appearance, malignant effusions, joint swelling	CBC abnormal (any cell line), or paradoxical inflammation with normal platelets and elevated ESR³; radiographs may show abnormalities
Spondyloarthropathies
	Arthritis with enthesitis	Ankle pain, heel pain, Achilles’ apophysitis, back or hip stiffness; pain typically worse at the end of the day	Inflammation and tenderness at sites of tendon insertion	Positive family history common
	Ankylosing spondylitis	Lumbar back pain and stiffness in young men; usually age 13 or older	Painful iritis common	HLA-B27 result usually positive; ANA result often negative; platelet count and ESR can be elevated
	Reactive arthritis (Reiter syndrome)	Painful joint with swelling following gastrointestinal or genitourinary infection; usually age 13 or older	Acute, asymmetric, lower-limb arthritis typical; painful iritis/conjunctivitis classic	HLA-B27 result usually positive; ANA result often negative
	Psoriatic arthritis	Psoriatic rash	Arthritis may precede psoriasis; dactylitis may occur.	HLA-B27 result often positive
	Arthritides of inflammatory bowel disease	Chronic or recurrent abdominal pain, weight loss or lack of appropriate weight gain, malaise	Large-joint arthritis	HLA-B27 result often positive; ANA result often negative
Systemic lupus erythematosus		Painful, typically symmetrical arthritis; more common in adolescents and in girls	Rash, arthritis, lymphadenopathy, central nervous system–related symptoms	High titers of ANA (typically > 1:640)⁴; presence of anti–double-stranded DNA; presence of anti-Smith antibodies; presence of anticardiolipin antibodies (in up to 65 percent of children with the disease)⁵; possible presence of lupus anticoagulant and antiphospholipid antibodies; cytopenias; low serum complement levels (falling serum complement levels [C3, C4, or both] may signal worsening disease and precede flares of renal involvement); nephritis