Rheumatoid factor-negative polyarticular juvenile idiopathic arthritis

What it is

From: Orphanet

A rare form of polyarticular juvenile idiopathic arthritis characterized by childhood-onset chronic arthritis of unknown cause involving five or more joints at disease onset and absence of rheumatoid factor IgM.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Abnormality of the wrist · Frequent (79-30%)

Abnormality of the wrist, the structure connecting the hand and the forearm.

Arthralgia · Frequent (79-30%)

Joint pain.

Arthritis · Frequent (79-30%)

Inflammation of a joint.

Elevated erythrocyte sedimentation rate · Frequent (79-30%)

An increased erythrocyte sedimentation rate (ESR). The ESR is a test that measures the distance that erythrocytes have fallen after one hour in a vertical column of anticoagulated blood under the influence of gravity. The ESR is a nonspecific finding. An elevation may indicate inflammation or may be caused by any condition that elevates fibrinogen.

Joint stiffness · Frequent (79-30%)

Joint stiffness is a perceived sensation of tightness in a joint or joints when attempting to move them after a period of inactivity. Joint stiffness typically subsides over time.

Synovial hypertrophy · Frequent (79-30%)

Synovial hyperplasia involves proliferation of mesenchymal stromal/stem cells and leads to synovial thickening, which can be observed radiographically.

Ankle swelling · Frequent (79-30%)

Enthesitis · Frequent (79-30%)

Joint swelling · Frequent (79-30%)

Knee osteoarthritis · Frequent (79-30%)

Synovitis · Frequent (79-30%)

Abnormal metatarsal morphology · Occasional (29-5%)

Abnormalities of the metatarsal bones (i.e. of five tubular bones located between the tarsal bones of the hind- and mid-foot and the phalanges of the toes).

Abnormality of metacarpophalangeal joint · Occasional (29-5%)

An anomaly of a metacarpophalangeal joint.

Abnormality of the cervical spine · Occasional (29-5%)

Any abnormality of the cervical vertebral column.

Other findings in the same source

From: Orphanet

Additional reported features include Abnormality of the hand (Occasional (29-5%)); Abnormality of the hip joint (Occasional (29-5%)); Abnormality of the shoulder (Occasional (29-5%)); Abnormality of the temporomandibular joint (Occasional (29-5%)); Anemia (Occasional (29-5%)); Antinuclear antibody positivity (Occasional (29-5%)); Flexion contracture (Occasional (29-5%)); Low-grade fever (Occasional (29-5%)); Lymphadenopathy (Occasional (29-5%)); Mild postnatal growth retardation (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

Childhood

Inheritance in the source

From: Orphanet

Multigenic/multifactorial

Which doctor should you see?

The suggested department for discussing Rheumatoid factor-negative polyarticular juvenile idiopathic arthritis is Rheumatology, with a rheumatologist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Are the findings inflammatory, structural or due to another mechanism?
• Is there evidence that other organs need assessment?
• How will function and any treatment-related risks be monitored?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Rheumatoid factor-negative polyarticular juvenile idiopathic arthritis. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.