Juvenile Idiopathic arthritis and infectious arthritis 郭三元 Division of R-I-A TSGH

Juvenile rheumatoid arthritis Juvenile chronic arthritis Juvenile Idiopathic arthritis

 Polyarticular type (20-30%)  Oligoarticular type (50-60%)  Systematic types (10%)  Enthesitis-related arthritis  Psoriatic arthritis 5 joints or more 4 joints or less

Juvenile idiopathic arthritis  Prevalence:12-113/100000, incidence 9- 25/  Age of onset < 16 years  Disease duration > 6 weeks  In oilgo- and poly- type: female > male, in systemic type: male=female  ESR usually elevated in poly- and systemic type, normal in oligo- type

Lab test  CBC, ESR, CRP  RF  ANA  HLA-B27  Ferritin  Anti-ccp

Genetic susceptibility  Spondyloarthropathy---HLA-B27  RF+ polyarticular – HLA-DR1 and HLA- DR4  Early onset of oligoarticular with chronic uveitis ---HLA-DR5 and HLA-DR8  Early onset oligoarticular --- HLA DQW1 and DPW2  Systemic type--- HLA-DR4

Polyarticular type  Symmetrical, large and small joints  Peak age of onset: 1-3 years  F:M: 3 : 1  Chronic uveitis: 5%  ANA: 40-50%  Positive RF –10%, increased risk of joint damage, more aggressive arthritis

Oligoarticular type  Peak age of onset: 2-5 years  F:M 5 : 1  High frequency of positive ANA (70-80%)  Chronic uveitis- related to positive ANA  RF: rare  Old age of onset (> 6 year), more often in males, with often HLA-B27 positive

 Localized inflammation and cytokine release  Increase blood flow -- macroepiphysis  Longer affected leg

 Evanescent skin rash (salmon-pink)  High fever  Polyarthragia/arthritis  F:M:1:1  RF: rare  ANA: <10%  Uveitis: rare  hepatosplenomegaly, lymphadenopathy, pericarditis  high ferritin Systemic type (Still’s disease)

Koebner phenomenon

Management  Minimize the joint damage, early diagnosis and early treatment  Keep muscle strong and limb in good position, keep joint moving  Physical therapy and exercise  Routine eye examination from 3-4 months interval to one year

Management  NSAIDs  Steroid  DMARDs  Biological agents ( anti-TNFα, anti-IL6)

Prognosis  Oligoarticular type: 80% resolved after 15 years, 15% develop polyarticular type with severe joints problems, 50% decreased visual acuity after 10 years ( uveitis ) and 25% developed cataract or glaucoma  Polyarticular type: RF(+) showed more severe course and only 33% became independent after 15 years  Systemic type : 50% remission, others developed severe arthritis and especially in cases of disease onset < 5 years-old

Growing pain  Age attacked: 4-12 years  F: M: 1:1  Deep aching, cramping pain in thigh or calf  Usually in evening or during the night, never in the morning  Normal physical examination and laboratory

Infection related arthritis

Septic arthritis  Acute onset of monoarthritis  Fever  Elevated ESR or CRP  Synovial fluid: WBC> 50000

Incidence of septic arthritis  2-5 /100,000/year in general population  /100,000/year in children  28-38/100,000/year in RA patients  40-68/100,000/year in prosthetic joint

Pathogenesis  Hematogenous route from a kind of remote infectious disease (70% ) – abundant vascular supply of synovium and lack of limiting basement membrane  dissemination from near osteomyelitis  Lymphatic spread from infection near the joint  Iatrogenic infections from arthrocentesis or arthroscope (20% )  Penetrating trauma from plant thorns or other contaminated objects

Predisposing factors  Impaired host defense  Direct penetration  Joint damage  Host phagocytic defect

Impaired host defense  Neoplastic disease  Elderly (>65 years)  Children (<5 years)  Chronic illness ( DM, cirrhosis, chronic renal disease, HIV)  Immunosuppressive agents

Direct penetration  Intravenous drug abuse  Puncture wounds  Invasive procedures

Joint damage  Prosthetic joints  RA  Hemarthrosis  OA

Host phagocytic defects  Complement deficiency  Impaired chemotaxis

Relate to joint  Knee  Hip  Ankle  Shoulder  Wrist  Elbow  Bursa

Radiological features  Joint effusion  Erosion  Joint space narrowing  Joint deformity  Osteoporosis  Bony ankylosis

Indication for surgical drainage  Hip and shoulder joint, S-C joint  Vertebral osteomyelitis with cord compression  Thick synovial purulent fluid or loculated  Persistent positive synovial fluid culture  Prosthetic joints  Associated with osteomyelitis  Delayed onset of therapy (>1 week)