Juvenile Idiopathic Arthritis
- Arthritis of unknown cause of >6 week duration in a child less than 16 years of age
- Arthritis is defined as a joint swelling with
- redness of joint
- warmth
- limitation of range of movement
Types of Arthritis
- Oligoarthritis
- involving four of less joints in the first 6 months of disease
- Extended oligoarthritis - involving more than 4 joints after 6 months of disease
- persistent oligoarthritis - involving only 4 or less joints even after 6 months of disease
- Polyarthritis
- involvement of five of more joints in the first 6 months of disease
ILAR Classification of JIA
DNB 1996, 2006, 2008, 2010, 2011, 2012, 2013, 2015, 2021, 2023
- Classification of JRA
- Types of JRA / JIA
- Diagnostic criteria for JIA
- ILAR classification
| type | criteria |
|---|---|
| Systemic JIA | - arthritis of more than 2 weeks (documented for atleast 3 days) - 1 or more of - HSM - Evanascent rash - Lymphadenitis - serositis |
| Oligo JIA | - involving four of less joints in the first 6 months of disease - Extended oligoarthritis - involving more than 4 joints after 6 months of disease - persistent oligoarthritis - involving only 4 or less joints even after 6 months of disease |
| RF + poly JIA | - involvement of five of more joints in the first 6 months of disease - RF positive (2 tests 3 months apart) |
| RF - poly JIA | - involvement of five of more joints in the first 6 months of disease - RF negative |
| Psoriatic | - arthritis with psoriasis - arthritis with 2 or more of - nail pitting - dactylitis - psoriasis in 1 degree relative |
| ERA | - enthesitis with arthritis - enthesitis or arthritis only with 2 or more of - lumbosacral tenderness or inflammatory sacroiliac pain - acute symptomatic anterior uveitis - HLA b27+ - onset in male > 6 years - history of ankylosing spondylitis, reiters, ERA in 1st degree relative |
| Undifferentiated | arthritis that fulfils none of more than 2 of the above |
Patterns
oligo JIA
- less than 5 year
- female
- no systemic features
poly JIA
- 8-10 year
- male
ERA
- 8-10 year
- male
- back pain
- difficulty in walking
- ankle pain (tendonitis)
- MRI
- erosion
- edema of bone marrow
- RF and ANA - negative
systemic
- systemic features
- koebner's phenomenon
- salmon colored patch
psoriatic
- family history of dermatological problem
- nail pitting
RF + vs RF -
RF +
- adult like
- symmetric
- small joint
- Aggressive diesase
- failure to thrive
RF -
- asymmetry
- TMJ joint involvement
- risk of uveitis
Differential Diagnosis
DNB 2004, 2011, 2013, 2014, 2015, 2023
Differential diagnosis of child with swelling for more than 6 weeks
single joint involvement
- septic arthritis
- TB arthritis
- Reactive arthritis
- Lymes
- malignancy
multiple joint involvement
- Connective tissue
- reactive arthritis
- lymes
- IBD associated
systemic features
- connective tissue disease
- neoplasia
- infection
- autoimmune
- IBD associated
non-inflammatory
- CAPA syndrome
- MPS
- Pseudorheumatoid dysplasia
Investigations
DNB 2011 DCH 2024
Investigation of JIA
Primarily Clinical diagnosis
- CBC - TLC and Platelets corresponds to systemic involvement, both with rise (if only one is elevated suspect malignancy), hb - low
- ESR - usually elevated
- CRP - elevated
- ANA
- LFT / KFT / SE
- HLA B27
- MRI - sacroiliac joint / TMJ
- Anti CCP - to determine the severity of JIA
- IGRA / Mantoux - before starting DMARD
radiology
- not much helpful
- done in
- monoarticular
- infectious
- sacroiliitis
- to access damage
Management
DNB 2006, 2010, 2012, 2014, 2018 DCH 2024
- Management of JIA
- principle of treatment of JIA
Drugs used
- NSAIDS
- Naproxen
- DMARDs
- Conventional
- Methotrexate
- Leflunomide
- Non conventional (biologicals)
- Anti TNF alpha
- eternacept
- adalimumab
- JAK inhibitors
- Tofacitinib
- Ruxolitinib
- Anti TNF alpha
- Conventional
- Corticosteroids
- adjuvent
- triamcinolone
- bridge therapy
- Physical / occupational therapy
Principle of treatment
ERA
- no role of Mtx in sacroiliitis
- give sulfasalazine
- bDMARDs
- no uveitis - etarnacept
- uveitis - adalimumab
oligo JIA
- NSAIDS
- intraarticualr steroids (IAGS) - triamcinolone
- cDMARDs if IA steroids fail
- bDMARDs if cDMARDs fail
poly JIA
- NSAIDs
- IAGSs - use cautiously - can cause hetrophic ossification
- cDMARDs - MTx > leflunomide
- bDMARDs - TNF alpha inhibitors
- early aggressive management
systemic JIA
- Anti IL1 (Anakinra), Anti IL6 (toziluzumab)
- NSAID - short course can be tried
- Oral steroids - pulse corticosteroids (recommended against as monotherapy)
- cDMARDs - not recommended
- calcineurin inhibitors and IVIG can be used in case of MAS
Periodic slitt lamp evalution for uveitis must be done in all children
drugs used in JIA
DNB 2014, 2023
Drugs used in JIA
TB screening for biologicals
- Always screen latent TB before starting biologicals
- choice of tests
- CXR
- IGRA
- Montoux
- Do CXR then proceed for montoux, IGRA
- If both IGRA and Montoux negative - start biologicals
- If either one is positive - start ATT (3HR), start biologicals after 1 month
- If frank TB, start appropriate TB regime, start biologicals after 3 months