Juvenile Idiopathic Arthritis Clinical Presentation

Arthritis must be present for 6 weeks before the diagnosis of juvenile idiopathic arthritis (JIA) can be made. Disease onset is either insidious or abrupt, with morning stiffness or gelling phenomenon (ie, stiffness after long periods of sitting or inactivity) being a frequent complaint and arthralgia occurring during the day. A morning limp that improves with time may be noted, and a toddler may no longer stand in the crib in the morning or after naps.

Complaints of joint pain may not be predominant in the patients’ history, however; children often stop using joints normally (eg, develop contractures of joints, decreased wrist range, limp) rather than complain of pain. Up to a quarter of children with oligoarticular JIA have no pain.

Individuals with JIA may have a history of school absences, and their ability to participate in physical education classes reflects the severity of the disease or acute flares.

Systemic-onset JIA is characterized by spiking fevers, typically occurring once or twice each day, at about the same time of day, with temperature returning to normal or below normal. The fever pattern is very useful because infections, Kawasaki disease, and malignancy usually do not have such a predictable pattern.

Systemic-onset JIA is usually accompanied by an evanescent rash (lasting a few hours), which is typically nonpruritic, macular, and salmon colored on the trunk and extremities. Occasionally, the rash is extremely pruritic and resistant to antihistamine treatment.

Children with psoriatic arthritis may have typical psoriasis but dermatological manifestations may be subtle; careful attention should be paid to looking for nail pits. Dactylitis is characteristic of psoriatic arthritis.

Enthesitis-related arthritis frequently presents as evening and post-exercise pain. Attention should be given to buttock pain and back pain that improves with activity (inflammatory back pain). These children cannot lie in bed all morning but have to get up due to back pain.

JIA is a clinical diagnosis. A complete physical examination is critical for the diagnosis. Physical findings are important to provide criteria for diagnosis and to detect abnormalities suggestive of alternative etiologies. The diagnosis of JIA is based on the physical finding of arthritis in at least 1 joint that has persisted for at least 6 weeks, with other causes excluded, in an individual younger than 16 years.

No diagnostic serologic tests for JIA are recognized, aside from rheumatoid factor assay for subclassification of polyarticular disease. Other tests, such as antinuclear antibody and HLA-B27 assays, may help further define diagnosis and risk of complications.

Arthritis is defined as either intra-articular swelling on examination or as limitation of joint motion in association with pain, warmth, or erythema of the joint. The hips, temporomandibular joint, and small joints in the spine do not demonstrate swelling when affected by synovitis but demonstrate the combination of loss of motion and pain. The physical findings in JIA are a reflection of the extent of joint involvement. ^[19]

In synovitis, in which there is synovial proliferation and an increase in joint volume, the joint is held in a position of maximum comfort. Limbs with synovitis are generally held in flexion. Range of motion often is limited only at the extremes.

In synovitis, the fingers may appear swollen, and the range of motion becomes painful. The wrist goes into flexion. In the knee, the parapatellar fossae often are obliterated, and a doughy synovium may be palpable. A soft, boggy swelling is appreciated in the popliteal fossa.

The hip is held in an attitude of flexion, abduction, and external rotation. Attempted range of motion will be painful to a varying degree. Guarding is an early sign of synovitis.

Cutaneous erythema is extremely rare in JIA. Its presence should alert one to look for another diagnosis.

A definite diagnosis of systemic-onset JIA must await the development of arthritis. This may occur at onset of the fever and rash or may lag by months or, rarely, years.

Physical examination findings include the following:

• The child appears systemically ill

• Arthralgia is often present

• The child may have generalized myalgia

• Evanescent, salmon-pink, macular rash (often linear) is found, predominantly on the trunk and the extremities; this rash, seen in the image below, is associated with fever spikes

  Systemic juvenile idiopathic arthritis (JIA) rash.

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• Hepatosplenomegaly is often present

• Lymphadenopathy is sometimes present, especially the axillary lymph nodes

• Muscle tenderness to palpation may be observed

• Serositis, including pleural and pericardial effusions, may be present, as is noted in the image below

  Child with pericardial effusion due to systemic onset juvenile idiopathic arthritis (JIA).

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• Chest pain or shortness of breath may be a sign of pericarditis or pleuritis

• Friction rub may occur in pericarditis but can be absent with a large pericardial effusion

• S₃, basilar rales, and hepatomegaly suggestive of heart failure may rarely be observed when myocarditis occurs in individuals with systemic-onset JIA

Characteristics of oligoarticular JIA include the following:

• In individuals with oligoarticular JIA, 4 or fewer joints (and in many cases, only 1 joint) are affected

• Large, weight-bearing joints, such as the knees and ankles, are typically affected, as seen in the image below

  Eighteen-month-old girl with arthritis in her right knee. Note the flexion contracture of that knee.

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• Children appear to be well, despite ambulating with a limp

• In cases of asymmetrical arthritis, chronic inflammation-related hyperemia in a knee or ankle may lead to overgrowth of that limb with subsequent leg-length discrepancy

• Muscle atrophy, often of extensor muscles (eg, vastus lateralis, quadriceps when the knee is affected), may occur

• Flexion contractures in the knees and, less commonly, the wrists are found

Involvement of a few small joints in the hands is atypical and suggests eventual development of polyarticular JIA or psoriatic arthritis. Dactylitis, or diffuse tenosynovitis of a finger or toe, also called a "sausage digit," is more typical of psoriatic arthritis or enthesitis-related arthritis.

Anterior uveitis (seen in the image below) is present in as many as 20% of children with oligoarticular and polyarticular JIA, especially those who are antinuclear antibody (ANA) positive. The uveitis is typically asymptomatic at onset and must be screened for with an ophthalmologic slit lamp examination.

Generally, children who were 6 years of age or younger at onset (especially of oligoarticular and psoriatic arthritis) and have a positive ANA test are screened by slit lamp exam every 3 months for 4 years or more and then every 6 months until at least 7 years after diagnosis. ^[20] Thereafter they are screened yearly for life.

Children who are at lesser risk (ie, have polyarticular disease and are ANA negative), are screened every 6 months for 7 years and then yearly. Children with systemic JIA are at very low risk and are screened yearly.

Acute anterior uveitis is one of the diagnostic criteria for enthesitis-related arthritis. These children with are screened initially and if symptomatic.

Older children with RF-positive polyarticular JIA should probably be screened yearly. There are few data on these children regarding their risk for uveitis.

Sequelae of chronic anterior uveitis. Note the posterior synechiae (weblike attachments of the pupillary margin to the anterior lens capsule) of the right eye secondary to chronic anterior uveitis. This patient has a positive antinuclear antibodies (ANAs) and initially had a pauciarticular course of her arthritis. She now has polyarticular involvement but no active uveitis. Image courtesy of Carlos A. Gonzales, MD.

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In polyarticular juvenile idiopathic arthritis, 5 or more joints are affected in the first 6 months after disease onset, weight-bearing joints are affected, rheumatoid nodules may be seen in patients with RF-positive disease, and symmetrical involvement of small joints in the hands is often found, as seen in the images below.

Patient with active polyarticular arthritis. Note swelling (effusions) of all proximal interphalangeal (PIP) joints in addition to boney overgrowth. Also note lack of distal interphalangeal joint (DIP) involvement. The patient has interosseus muscle wasting (observed on the dorsum of the hands), and subluxation and ulnar deviation of the wrists are present. Image courtesy of Barry L. Myones, MD.

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Wrist radiographs of the patient with active polyarticular arthritis shown in Media file 2. Note severe loss of cartilage in the intercarpal spaces and the radiocarpal space of the right wrist. A large erosion is present in the articular surface of the ulnar epiphysis. The view of the left wrist shows boney ankylosis involving the lateral 4 carpal bones with sparing of the pisiform. Erosions are present in the distal radius and ulna. Almost a loss of cartilage has occurred between the radius and ulna and the carpus. Narrowing of the carpal/metacarpal joints is present. Image courtesy of Barry L. Myones, MD.

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Close-up of the proximal interphalangeal (PIP) effusions in the patient with active polyarthritis shown in Media files 2 and 3. Synovial thickening and effusion, as well as boney overgrowth, are present at the PIP joints bilaterally. Image courtesy of Barry L. Myones, MD.

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Patient with inactive polyarticular arthritis. Long-term sequelae of polyarticular disease includes joint subluxation (note both wrists and thumbs), joint contractures (at proximal interphalangeal joints [PIPs] and distal interphalangeal joints [DIPs]), boney overgrowth (at all PIPs), and finger deformities (eg, swan-neck or boutonniere deformities). Image courtesy of Barry L. Myones, MD.

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Hand and wrist radiographs of the patient with inactive polyarticular arthritis shown in Media file 5. Long-term sequelae of polyarticular disease includes periarticular osteopenia, generalized increase in the size of epiphyses, accelerated bone age, narrowed joint spaces (especially at the fourth and fifth proximal interphalangeal joints [PIPs] bilaterally), boutonniere deformities (at left third and fourth interphalangeal joints), and medial subluxation of the first metacarpophalangeal joints (MCPs) bilaterally. Flattening and erosion of the radial carpal articular surface is present in both wrists. Mild narrowing of the joint spaces exists at the carpometacarpal joints and intercarpal rows bilaterally, with sclerotic change of the intercarpal row (right > left). The trapezium and trapezoid may be fused bilaterally. Image courtesy of Barry L. Myones, MD.

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Decreased extension of the cervical spine is often asymptomatic. It is indicative of arthritis of the cervical spine and can lead to subluxation, typically of the C2 vertebra on C3. Fusion of the posterior elements of the vertebra may occur. (See the image below.)

Flexion and extension views of C-spine in child with poorly controlled polyarticular juvenile idiopathic arthritis (JIA).

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Arthritis of the temporal-mandibular joint (TMJ) may lead to micrognathia. TMJ arthritis is typically asymptomatic; decreased mouth aperture, lateral deviation of the jaw gait, or auscultatory abnormalities over the TMJ are signs of underlying arthritis (see the image below).

Temporal-mandibular joint (TMJ) MRI postgadolinium infusion. Abnormal increased uptake indicative of synovitis in child with polyarticular juvenile idiopathic arthritis (JIA).

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Psoriatic arthritis in children is usually mild. Onset of arthritis precedes that of psoriasis in approximately half of children.

Characteristics of psoriatic arthritis include the following:

• Monoarticular arthritis (50% of children)

• DIP joint involvement (50%)

• Tenosynovitis (30%)

• Nail involvement(71%) - pitting is the most common but least specific finding

• Disordered bone growth with resultant shortening (47%)

• Sacroiliitis (28%)

For further discussion of this disorder, see Psoriatic Arthritis.

Enthesitis-related arthritis, or pediatric spondyloarthropathy, is characterized by periods of inflammation of tendons and ligaments, particularly at the area of insertion into bone (entheses). Often, children and adolescents with spondyloarthropathy present with arthritis, making the distinction between subtypes difficult. Furthermore, children occasionally develop a disease that appears to be a combination of the 2 diseases.

Pain and tenderness at the enthesis is the most common manifestation, but swelling may also be seen. In children, the initial manifestations involve mainly the peripheral joints (eg, dactylitis) with asymmetric oligoarticular arthritis of the lower limbs; axial involvement (eg, sacroiliitis) tends to appear later in the disease course. ^[15]

Diagnostic criteria for enthesitis-related JIA are the presence of both arthritis and enthesitis, or the presence of arthritis or enthesitis along with any 2 of the following 5 manifestations ^[21] :

• Sacroiliac tenderness and/or inflammatory lumbosacral pain

• Positive human leukocyte antigen B27 (HLA-B27) test

• Onset of arthritis in a male 6 years old or older

• Acute symptomatic anterior uveitis

• Presence in a first-degree relative of ankylosing spondylitis, enthesitis-related arthritis, inflammatory bowel disease with sacroiliitis, reactive arthritis, or acute anterior uveitis

Although enthesitis can be observed in persons with oligoarticular and polyarticular JIA, the eventual development of arthritis into a predominant enthesitis is more characteristic of spondyloarthropathy. The radiographic changes observed in adults (eg, sclerosis of the sacroiliac joints, bamboo spine) are rare in childhood and adolescence.

Undifferentiated JIA is diagnosed if the patient’s manifestations either do not fulfill the criteria for any one category or fulfill the criteria for more than one.

Most often, children in the latter category fulfill the criteria for polyarticular RF-negative JIA and either enthesitis-related JIA or psoriatic JIA. ^[21]

Systemic-onset juvenile idiopathic arthritis

The complications that may occur in systemic-onset JIA are pericarditis, hemolytic anemia, macrophage activation syndrome (MAS), and endarteritis. Patients with pericarditis often present with orthopnea and respond to intravenous (IV) corticosteroid treatment.

MAS is a rare, but important, complication, in which all 3 bloodlines become rapidly decreased. Hypofibrinogenemia, thrombocytopenia, and elevated aspartate aminotransferase levels and markedly elevated ferritin levels are hallmarks. Hypotension, central nervous system (CNS) disease, and marked hepatosplenomegaly may be noted as complications of a release of massive amounts of cytokines.

Children with limited arthritis

Complications of oligoarticular JIA and psoriatic arthritis include joint contractures, uveitis, and leg-length discrepancy. Uveitis is almost always asymptomatic and more frequent in young girls who have positive levels of antinuclear antibody. Evaluation with a slit-lamp every 4 months by a pediatric ophthalmologist can detect early disease to prevent permanent eye damage and even blindness.

Leg-length discrepancy may complicate unilateral knee involvement. In young children, it may result from neovascularization of growth plates, so the involved limb is longer. In early puberty, unilateral arthritis can lead to premature fusion of the epiphysis, in which case the short limb is on the affected side. The problem may not be detected in patients with a knee flexion contracture until the contracture is corrected. Both flexion contractures and leg-length discrepancies are much less frequent with early intervention.

Children with widespread arthritis

Complications of polyarticular JIA include skeletal abnormalities such as increased size of epiphyses, accelerated bone age, narrowed joint spaces, swan-neck and/or boutonniere deformities, joint subluxation, and cervical spine involvement.

Difficulty extending the spine may create a problem for intubation prior to surgery, so anesthesiologists need to be informed of the patient's diagnosis. Cervical spine radiography (in flexion and extension) may help to screen for potential difficulties during induction of anesthesia. High-level subluxation is a potential complication.

Enthesitis-related arthritis

Complications of enthesitis-elated arthritis are rare but can include restrictive lung disease and aortic insufficiency. These children are at risk for symptomatic iritis with acute photophobia and conjunctivitis but only rarely does it lead to visual impairment.