#30: A Joint Approach to JIA

July 28, 2021 | By Sam Masur

Juvenile Idiopathic Arthritis w. Dr. Johnson

Summary

Rheuminating on juvenile idiopathic arthritis? Pediatric rheumatologist extraordinaire Dr. Nicole Johnson walks us through the history and evaluation of pediatric arthritis. She teaches us all about the clinical diagnosis and treatment of the seven subtypes of JIA.

Credits

• Producer: Becca Raymond-Kolker MD & Nicholas Lee MD
• Executive Producer: Nicholas Lee MD
• Writer: Becca Raymond-Kolker MD
• Infographic: Becca Raymond-Kolker MD
• Cover Art: Chris Chiu MD
• Hosts: Chris Chiu MD & Justin Berk MD
• Editor:Justin Berk MD; Clair Morgan of nodderly.com
• Guest(s): Nicole Johnson MD

JIA Pearls

1. The most important part of evaluating joint pain is the history, physical examination, and impact on the patient’s life!
2. JIA is a clinical diagnosis that includes:
   1. One or more joints involved
   2. Onset at age < 16 years old
   3. Length of arthritis > 6 weeks
   4. Ruled-out other etiologies, such as malignancy
3. There are 7 subtypes of JIA. Subclassification is clinically useful in providing appropriate counseling, screening for common complications, and expectations regarding treatment.
4. Aggressive treatment at initiation is typically warranted to help tamp down inflammation and preserve joint function.

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JIA Notes 

The Evaluation of Joint Pain

The most important part of evaluating joint pain is the history, physical examination, and impact on the patient’s life!

History

Dr. Johnson recommends a thorough history because it will help you delineate your further work-up and will come in handy when attempting to make a diagnosis later on. These are the areas that she recommends to focus on:

• Location: Is it the actual joint, above the joint, or surrounding the joint? This will help you distinguish whether it is the joint space or soft tissue.

• Timing: What time of day does it hurt the most? Is it in the morning that improves, happens in the afternoon, or is it worse after use?

• Duration: How long has this joint pain been present? Has it ever happened before?

• Severity: Since the joint pain has been present, is it improving, worsening, or stable?

• Exacerbation: What movements/factors make the pain better or worse?

• Systemic symptoms: What other organ systems are involved? This helps flesh out your differential diagnosis – are there fevers, mouth sores, vision changes, or rashes? JIA is a diagnosis of exclusion and needs everything else ruled-out.

Physical Exam

• The Entrance: Watch how the child walks into the room and moves onto the examination table. Do they hold their limbs in a certain position?

• The Exam: Dr. Johnson’s expert opinion is to tell them that it is like gym class! You are going to do a lot of motion and stretching to help determine what is involved.

• Tip: Evaluate for symmetry – use the other side as reference

• Trick: Look for differences that could indicate chronicity, such as a leg length difference or swelling of the joint on one hand!

What is arthritis and how to determine it on examination?

The easiest way to determine arthritis is when there is a large, swollen joint. The more subtle findings that are suggestive of arthritis are the following:

• Redness or warmth to palpation
• The patient positions the joint in an odd position to avoid pain

Red Flags

• The pain or symptoms are severe enough that the patient is losing function (unable to perform a sport they previously enjoyed or keep up with a peer)
• Do not forget to evaluate for red flags of malignancy or infection that can cause arthritis!

JIA Evaluation and Diagnosis

Juvenile Idiopathic Arthritis came into terminology because countries across the world were using disparate terms to describe the same entity. An international collaboration determined that JIA would be the best term because it is truly “idiopathic” and a diagnosis of exclusion.

Diagnostic Criteria

• • One or more joints involved
  • Onset at age < 16 years old
  • Length of arthritis > 6 weeks
  • Ruled-out other etiologies, such as malignancy

• Testing not required, although it helps rule-out other diagnoses

Sub-classifications of JIA

Why do we subclassify JIA? Dr. Johnson’s expert opinion is that we do so to stratify patients by what complications they are most at risk for (to counsel appropriately) and that it impacts treatment (given that some sub-classifications are more aggressive towards joints).

1. Oligoarthritis
2. Polyarthritis (RF negative)
3. Polyarthritis (RF positive)
4. Psoriatic arthritis
5. Enthesitis-related arthritis
6. Systemic onset juvenile idiopathic arthritis
7. Undifferentiated arthritis

Lab Work in JIA

JIA is truly a clinical diagnosis. There is no lab work that rules-in a diagnosis of JIA. The rheumatoid factor can be helpful but it is only positive in < 10% of patients diagnosed with JIA. Where it can be helpful is determining if there are other concomitant diseases.

JIA Treatment and Complications

Treatment

• Aggressive treatment at initiation is typically warranted to help tamp down inflammation and preserve joint function
• While this can include steroids initially, the mainstays of therapy are steroid-sparing therapy
• The focus is now on disease modifying anti-rheumatic drugs (DMARDs), such as methotrexate and biologic therapy
• 1st line: methotrexate
• 2nd line: add on a biologic
• Monitoring of methotrexate: Evaluate periodically for leukopenia and liver injury
• Dose titration of methotrexate is typically limited by nausea; be sure to counsel and symptomatically treat this!

Common Complications

• Uveitis (with or without symptoms)
• Serositis (can involve pericardium or pleura and be life-threatening)
• Secondary osteoarthritis or growth issues
• Macrophage activation syndrome

Other Stuff

Black Man in a White Coat by Damon Tweedy

Philly D.A. Miniseries Documentary on PBS 

Goal

Listeners will explain the evaluation,  clinical diagnosis, and management of juvenile idiopathic arthritis. 

Learning objectives

After listening to this episode listeners will…  

1. Recognize the importance of history and physical exam in the evaluation of pediatric arthritis. 
2. Be familiar with the diagnostic criteria of juvenile idiopathic arthritis.
3. Describe the seven subtypes of JIA and their distinguishing features.
4. Describe the role of labwork in the diagnosis and management of JIA.
5. Learn about the general approach and goals of treatment.
6. Feel comfortable discussing common complications of JIA.

Disclosures

Dr Johnson reports no relevant financial disclosures. The Cribsiders report no relevant financial disclosures. 

Citation

Raymond-Kolker R, Lee N, Johnson N, Masur S, Chiu C, Berk J. “A Joint Approach to JIA”. The Cribsiders Pediatric Podcast. https:/www.thecribsiders.com/ July 28, 2021.