Clean FRCS notes with inline figures
Recurrent knee effusion in a child
•Ddx: infection, trauma (NAI), inflammatory (JRA), hemophilia
JRA/ juvenile idiopathic arthritis:
•A persistent autoimmune inflammatory arthritis lasting > 6 weeks in a patient younger than 16 years of age
•Genetics: HLA-DR4 (poly-arthritis), HLA- DR8, 5, 2.1/ HLA B27 (pauciarthritis)
Diagnosis by exclusion
Types:
•Polyarthritis (similar to RA) – 25-40%
•Oligoarthiritis (similar to seronegative, commonly associated with eye problem) – 50%
•Systemic (Still disease) – 10-20%
Clinical features:
•General
•Intermittent fever
•Rash
•Pericarditis
•Iridocyclitis (Inflammation of iris and ciliary body)
•Ortho
| Type / group | Definition / note |
|---|---|
| C | spine involvement (kyphosis, facet ankylosis, and atlantoaxial subluxation) |
•Tenosynovitis
•Morning stiffness
•Osteoporosis with easy fracture
•Growth retardation (Suppression by corticosteroid)
•Ankylosis of joint in systemic type
•Deformity
•External torsion of the tibia
•Dysplasia of distal ulna
•Underdeveloped mandible (micrognathia)
•Short neck and scoliosis
Still disease:
•Acute presentation (multiple joint involvement, fever, salmon coloured rash, and splenomegaly)
•Usually <3 y.o
Prognosis:
•50% spontaneous resolve, 25% slight limitation, 25% severe disability
Investigation:
Xray:
•juxta-articular, late osteopenia and joint destruction
•C spine Xray for atlantoaxial instability
•Blood test: RF (worse prognosis if +ve), ANA (+ve is diagnostic), HLA typing
Treatment:
•Physiotherapy to maintain range and power
•DMARD (azathioprine, etanercept) and biological agent (rituximab)