Arthralgia/arthritis in children

Probability diagnosis

Juvenile idiopathic arthritis (incl. still disease and psoriasis)

Viral polyarthritis (e.g. parvovirus, rubella)

Growing pains (leg)

Irritable hip (transient synovitis)

Traumatic arthritis

Reactive arthritis (post-infective)

Serious disorders not to be missed

Vascular (haematological disorders):

• thalassaemia

• sickle cell anaemia

• haemophilia

Infection:

• rheumatic fever

• septic arthritis

• osteomyelitis

• meningococcaemia

• tuberculosis

• HIV

Cancer:

• leukaemia

• lymphoma

• neuroblastoma

Other:

• juvenile rheumatoid arthritis

Pitfalls (often missed)

Hip disorders:

• Perthes disease

• slipped upper femoral epiphysis

Osteochondritis dissecans

Henoch-Schönlein purpura

Kawasaki syndrome

Rarities:

• scurvy

• rickets

• periodic fever syndrome

Masquerades checklist

Drugs (e.g. penicillins, cotrimoxazole)

Spine: juvenile ankylosing spondylitis

Key history and features in childhood

Arthralgia (joint pain) is a common problem in childhood. The complaint demands respect because of the many serious problems causing it. Arthritis may be part of an infectious disease such as rheumatic fever, rubella, varicella, human parvovirus, influenza or other viral infection and is seen with Henoch-Schönlein purpura. Actually viral polyarthritis is very common in children. An FBE is helpful as it may show lymphopaenia, lymphocytosis or atypical lymphocytes.

Diagnostic tips

• Acute onset monoarticular arthritis associated with fever is septic until proved otherwise.

• 5% of all children complain of recurrent limb pain, which often awakens them from their sleep. A careful history and physical examination are essential and perhaps simple basic investigations may be appropriate.

• Growing pains and post-activity musculoskeletal pain are relatively common.