· heterogenous group of disorders characterised by
· inflammatory joint disease
· non-infective
· more than 3 months duration
· in children under 16
· affects 1 per 1000 children
· equal sex incidence
· different subgroups have association with different HLA types
· unknown
· immune abberation suspected
· similar to rheumatoid disease
· genetic predisposition
· infectious trigger
· three types
· makes up 20%
· Still’s disease
· makes up 40%
· divided into
· early onset
· late onset (like ankylosing spondylitis)
· makes up 40%
· divided into
· seronegative
· seropositive (like RA)
· classical Still’s disease
· usually age < 3 yrs
· boys : girls equal
Onset
· intermittent features
· almost daily
· child quite sick then improves
· features are
· fever to 40o
· maculopapular rash
· malaise
· lymphadenopathy
· hepatosplenomegaly
Joints
· symptoms occur weeks to months after onset
· initially mild swelling and pain
· usually resolves with systemic illness
· may progress to polyarthritis
· most commonly knees and wrists
· also ankles and tarsi
· involves flexor tendons of fingers
· may be MCP and PIP joint swelling
· if active disease persists, extends to other joints
· hip
· cervical spine
· may stunt growth
· abetted by corticosteroids
· 4 or less joints in 1st 3 months
· no systemic illness
· subdivided into two groups depending on age
Early onset
· age < 6 yrs
· girls > boys
· most commonly involves medium joints
· knee
· ankle
· elbow
· may have single finger with
· flexor tenosynovitis
· PIP joint swelling
· carry antinuclear antibodies
· 50% develop chronic iridocyclitis
· resolves after few years
· usually left with asymmetric deformities
Late onset
· age > 9 yrs
· boys > girls
· most develop sacroiliitis and spondylitis
· associated with family history
· usually positive for HLA B27
· rheumatoid factor negative
· lower limbs affected
· knee, ankle, hip
· may be enthesitis
· plantar fascia and Achilles tendon
· tibial tubercle and patella
· greater trochanter
· 5 or more joints within 1st 3 months
· girls > boys
· two subtypes depending on presence of RF
Seronegative
· much more common (85%)
· similar to polyarthritis following systemic onset
· affects
· knees most commonly
· wrists and ankles
· cervical spine
· hand with flexor tenosynovitis
· foot with 1st MTP jt involvement
· if persists, spreads to other joints
Seropositive
· older girls
· similar to RA
· small joints of hands and feet
· wrists
· rheumatoid nodules
· positive rheumatoid factor
· rapidly progressive with joint destruction
· called ‘juvenile rheumatoid arthritis’
Systemic
· ESR usually > 100
· significantly elevated WCC with neutrophilia
· mild anaemia (10 g/dl)
· increased IgG
· rheumatoid factor absent
Pauciarticular
· normal or mildly elevated ESR
· normal FBC
· ANAs may be present
Polyarticular
· ESR 60-70
· mildly elevated WCC
· rheumatoid factor present in seropositive form
· non-specific changes early
· have severe periarticular (epiphyseal) osteopaenia
· may be progressive joint erosion and deformity later
· systemic
· viral illness
· pauciarticular
· septic arthritis
· tuberculous synovitis
· rheumatic fever
· bleeding disorders
· leukaemia
· for both parents and children
General
· prolonged bed rest should be avoided
· required for systemic disease
· attention to joint position
· contractures are major problem
· period of prone lying daily
· resting splints for
· wrists, knees and ankles
· working splints for
· wrist for writing
· neck for schoolwork
· knees when walking if weak quads
· may require skin traction for acute spasm or contractures of hips or knees
Local
· splintage can rest joint flare-up
· maintain ROM
· daily movement through range
· minimise muscle wasting
· daily gentle exercises
· mainstay of treatment
· salicylates less often used because of Reye’s syndrome
· paediatric NSAID suspensions available
General
· intravenous immunoglobulins for systemic features
· methotrexate for severe disease
· other drugs generally not useful
Seropositive
· gold and penicillamine useful
Spondyloarthropathy
· sulphasalazine effective
Systemic
· do not affect
· progress of disease
· occurrence of complications
· use limited by side-effects
· growth retardation
· osteoporosis
· indications
· systemic illness unresponsive to other therapy
· polyarthritis unresponsive to other therapy
· should use alternate day therapy to minimise growth retardation
Intraarticular
· useful for flares of pauciarticular disease
· knee
· flexor sheaths
Topical
· for iridocyclitis
· general retardation of growth
· abetted by prolonged corticsteroid therapy
· epiphyseal disturbances lead to typical deformities
· external torsion of tibia
· dysplasia of distal ulna
· underdevelopment of neck
· scoliosis
· most common with seropositive disease
· common deformities
· protrusio acetabulae
· atlantoa[PL1]xial subluxation
· finger subluxation
· more common if under 5 with osteoporosis
· in pauciarticular disease
· may lead to blindness
· more common with longstanding systemic disease
· may be fatal
· mortality uncommon
· two main causes
· infection early
· amyloidosis late
· 75% of patients enter long remission and have little or no residual disability
· poor outcome more likely with
· early onset (< age 1)
· extended duration of active disease (5 yrs)
· most serious joint involvement is hip
· early onset and prolonged disease leads to developmental hip abnormalities
· leads to early degenerative changes