Juvenile Idiopathic Arthritis Flashcards
Define “juvenile idiopathic arthritis”
Arthritis occurring in someone who is less than 16 years old that lasts for more than 6 week
Types of JIA
Systemic
Polyarticular
Oligoarticular
Enthesitis-related
Juvenile psoriatic
Clinical features of systemic JIA
Subtlesalmon-pink rash
High swinging fevers
Enlarged lymph nodes
Weight loss
Joint inflammation and pain
Splenomegaly
Muscle pain
Pleuritis and pericarditis
Investigations in systemic JIA
Antinuclear antibodiesandrheumatoid factorsare typically negative
Raisedinflammatory markers, with raisedCRP,ESR,plateletsandserum ferritin
Complications in systemic JIA
Macrophage activation syndrome(MAS), where there is severe activation of the immune system with a massive inflammatory response
Presentation of macrophage activation syndrome
Acutely unwell child with disseminated intravascular coagulation (DIC), anaemia, thrombocytopenia, bleeding and a non-blanching rash
Non-infective differentials in children with fever >5 days
Kawasaki disease
Still’s disease
Rheumatic fever
Leukaemia
Define polyarticular JIA
Idiopathic inflammatory arthritis in 5 joints or more
Clinical features of polyarticular JIA
Tends to besymmetrical
Can affect small joints of the hands and feet, as well as large joints such as the hips and knees
Minimal systemic symptoms
Can bemild fever,anaemiaandreduced growth
Systemic symptoms are mild, unlike systemic onset JIA
Define oligoarticualr JIA
Involved 4 joints or less
Usually only affects a single joint (mono arthritis)
Clinical features of oligoarticular JIA
Monoarthritis
Tends to affect larger joints e.g. knee or ankle
Anterior uveitis
Tend not to have any systemic symptoms
Inflammatory makers will be normal or mildly elevated
Antinuclear antibodiesare often positive
Rheumatoid factor is usually negative
Define enthesitis-related arthritis
Paediatric version of theseronegative spondyloarthropathygroup of conditions that affect adults (ankylosing spondylitis,psoriatic arthritis,reactive arthritisandIBD-related arthritis)
What is an enthesis?
Point at which tendon of a muscle inserts into bone
Causes of enthesitis
Traumatic stress, such as through repetitive strain during sporting activities
Autoimmune inflammatory process
Clinical features of enthesitis-related JIA
Consider signs and symptoms ofpsoriasis(psoriatic plaques and nail pitting) andIBD(intermitted diarrhoea and rectal bleeding)
Prone toanterior uveitis
Tender to localised palpation of theentheses
Key areas in enthesitis-related JIA
Interphalangeal joints in the hand
Wrist
Over the greater trochanter on the lateral aspect of the hip
Quadriceps insertion at theanterior superior iliac spine
Quadriceps and patella tendon insertion around the patella
Base of achilles, at the calcaneus
Metatarsal heads on the base of the foot
Define juvenile psoriatic arthritis
Seronegative inflammatory arthritisassociated withpsoriasis
Investigations in juvenile psoriatic arthritis
Clinical diagnosis
Exclude other causes
Clinical features of juvenile psoriatic arthritis
Plaques of psoriasison the skin
Nail pitting
Onycholysis
Dactylitis, inflammation of the full finger
Enthesitis
Medical management of juvenile psoriatic arthritis
NSAIDs (symptom control only)
Steroids (intra-articular or oral)
Immunotherapy:
DMARDs e.g. methotrexate first line, sulfasalazine, leflunomide
Biologics e.g. TNF-a inhibitors)
Complications of juvenile psoriatic arthritis
Flexion contractures (requiring physio and splints)
Joint destruction (requiring prostheses at young ages)
Growth failure (from steroids and chronic disease)
Chronic anterior uveitis (causing visual impairment)
1/3 of children with juvenile idiopathic arthritis continue to have joint pain into adulthood
