The limping child

includes: Juvenile idiopathic arthritis

Limp is a common presentation in paediatrics and has a range of benign and mores serous causes. Common differentials to consider in a limping child (by age) are shown in the table below:

Causes of limp by age
	0-3 years	4-10 years	11-16 years
Most common	Trauma (including toddler's fracture)	Trauma Transient synovitis Perthes' disease	Trauma Osgood-Schlatter disease
Conditions requiring urgent intervention	Osteomyelitis Septic arthritis Non accidental injury (NAI) Malignancy (e.g. neuroblastoma) Testicular torsion Inguinal hernia	Osteomyelitis Septic arthritis NAI Malignant disease (e.g. acute lymphocytic leukaemia) Testicular torsion Appendicitis Inguinal hernia	Osteomyelitis Septic arthritis Slipped upper femoral epiphysis (SUFE) Malignancy (e.g. bone tumours) Testicular torsion Appendicitis Inguinal hernia
Other important conditions to consider	Developmental dysplasia of the hip Juvenile Idiopathic Arthritis	Juvenile Idiopathic Arthritis	Juvenile Idiopathic Arthritis
	Metabolic (e.g. rickets) Haematological disease (e.g. sickle cell anaemia) Reactive arthritis Lyme arthritis Multisystem diseases (e.g. Juvenile Systemic Lupus Erythematosus, Juvenile Dermatomyositis)

Indications for urgent assessment of a limping child

The very young (under 3 years of age)
The ill and febrile
The non-weight bearing
Children with painful restricted hip movements
The child who is immunosuppressed Essentially when septic arthritis, osteomyelitis, fractures, non accidental injury, SUFE and malignancy are suspected

Investigations will depend on the suspected cause of the limp. Discuss management with seniors and the orthopaedic team.

Juvenile Idiopathic Arthritis (JIA)

Background

Group of conditions involving arthritis with or without other clinical features
Idiopathic inflammatory condition, probably Autoimmune
UK prevalance 1/1000 (Malawi unknown), Female> male, onset commonest in < 6 years

Diagnosis

Requires symptoms to have been present for > 6 weeks
Requires onset of arthritis at age < 16 years

Commoner Subtypes (International league of associations for rheumatology, ILAR)

Arthritis Type	Diagnostic Features	Outlook	Other
Systemic (SO-JIA)	Arthritis AND fever of at least 2 weeks PLUS AT LEAST ONE OF: serositis, evanescent rash, hepatosplenomegaly, lymphadenopathy	Variable. Systemic features usually settle but arthritis may continue for several years
Oligoarthritis (OA-JIA)	Arthritis in 4 or less joints. If further joints become involved > 6 months later this is called oligo extended JIA	Usually good, rarely causes joint damage if treated and usually remits by adulthood (unless it is the extended type)	Commonest subtype, high risk for anterior uveitis
Polyarthritis (PA-JIA)	Arthritis in 5 or more joints. Can be rheumatoid factor positive or negative	Can continue into adulthood or remit	Can be associated with fatigue and low grade fever

History

Joint symptoms: Pain stiffness and swelling which is worst in the morning or after a period of sitting still; which joints affected, symmetry; variation of symptoms throughout the day; gait abnormalities, activity limitations
Other features of JIA: fevers, skin changes (rashes, bruising), breathlessness (pleuritic/pericarditis), visual symptoms (uveitis); red flags for other conditions: malignancy, TB, septic arthritis/ sepsis (especially if immunocompromised)
Family history: arthritis, psoriasis, autoimmune conditions

Examination

Joints: LOOK (swelling, deformity, colour changes), FEEL (heat, tenderness), MOVE (passive and active) every joint. Don’t forget spine and temperomandibular joints. pGALS is a good screening tool (see overleaf for details),
Systemic: lymphadenopathy, hepatosplenomegaly, pleural/pericardial effusions (can all be seen in SO-JIA), features of psoriasis, rashes,

Important differentials include

Septic arthritis: UNILATERAL SWOLLEN JOINT, PAIN AND FEVER NEEDS URGENT ORTHOPAEDIC CONSULTATION (see Swollen joint)
Malignancy (e.g. bone tumours, leukaemia). Perform diagnostic work up if any suspicion
Acute Rheumatic fever
HIV arthropathy
Tuberculosis
Joint bleeds e.g. in haemophilia
Other autoimmune conditions and vasculitides eg Henoch Schonlein Purpura (HSP), Systemic Lupus Erythematosus (SLE), dermatomyositis

Investigations

in patients without red flag features who have symptoms for > 6 weeks and are presumed to have JIA

HIV testing
Malignancy/ TB work up if suspicion
FBC (often normal in oligoarticular. In systemic onset JIA/ polyarticular it can reveal normo/microcytic anaemia and leucocytosis or thrombocytosis)
ESR ↑↑↑ in SO-JIA, can be ↑↑/↑/- in PA-JIA, ↑/- in OA-JIA (normal ESR 0- 20 mm/h)
CXR/ECHO if suspicion of alternate diagnosis or pleuritis/pericarditis
X rays may reveal deformities, erosions, joint space narrowing, but can be normal in early disease
Ultrasound of joints useful if expertise exists to show joint effusions

Management

For all patients

General exercise promotion and physiotherapy (physios can arrange casting of joints with a fixed flexion, ankle foot orthoses and walking frames if needed). Maintaining ambulation very important
NSAIDs: Used for control of pain and stiffness but are not disease modifying. Ibuprofen dose = 10mg/kg 3 or 4 times daily (higher than standard dose)
Follow up in general clinic (Wed afternoon 1:30 pm in under 5)
Opthalmology assessment at diagnosis then yearly to look for anterior uveitis - this may be asymptomatic and is potentially sight threatening so very important

For some patients (discuss with consultant)

Oral prednisolone 1mg/kg/day (max 60 mg od) in acute flare of SO-JIA or PA-JIA. Use 2mg/kg/day if there is overwhelming systemic inflammation. Need to taper steroid dose, NEVER STOP SUDDENLY. Patients on ibuprofen and steroids should be started on Omeprazole.
Methotrexate: 0.3 to 1 mg/kg PO once weekly on the same day of each week, maximum 30 mg/week plus Folic acid 5 mg OD. Patients should be warned about possible side effects of immune suppression, rashes, liver inflammation. High doses > 20mg may cause nausea and vomiting so enquire about this/ compliance if on such a dose. Methotrexate should be continued for 2 months following remission of symptoms (d/w consultant before stopping). Check FBC, Creatinine and LFTs at base line and every 3 months.
Intra-articular joint injections (can be arranged at Beit CURE)

pGALS (paediatric gait, arms, legs, spine) screen-validated for use in school aged children

Screening questions

Do you have any pain or difficulty in moving your arms, legs, neck or back?
When you get dressed, are you able to do this yourself without any help?

Then an examination (if all is normal it makes musculoskeletal pathology very unlikely)

Observe the child from the back front and side
Observe the patient walking.
'Walk on your heels.'
'Walk on your tip-toes.'
'Put your hands out in front of you.'
'Turn your hand over and make a fist.'
'Touch the tips of your fingers.'
Squeeze MCPJs.
'Put your hands and wrists together.'
'Put your hands back to back.'
'Reach up as far as you can.'
'Look at the ceiling.'
'Put your hands behind your neck.'
'Place your ear on your shoulder.'
'Open your mouth wide and place 3 fingers inside.'
Feel for effusion at the knee.
'Bring your ankle up to your bottom.'
Passive movement of hip and knee including rotation of hip.
Observe curvature of spine from the side and behind. 'Bend forwards.'

References
BMJ Best practice, Juvenille Idiopathic Arthritis. June 2015 [online]
http://www.arthritisresearchuk.org/health-professionals-and-students/videoresourcespgals.aspx/