1. A limp persisting beyond four weeks warrants referral
A limp which has been present since the child started walking may be a congenital or neuromuscular disorder but this article will cover assessment of an acquired limp. Assess limping children carefully to exclude rare but serious causes of limp.1
If the diagnosis is not clear then it is important parents know when to reattend. A limp persisting beyond four weeks without a confirmed diagnosis warrants a referral to assess for childhood arthritis. Reactive arthritis – arthritis following infection – shouldn’t persist beyond six weeks.
2. Age is key in the differential diagnosis
Age is very helpful in determining the differential diagnosis of the limping child. Trauma, infection, reactive arthritis, malignancy, referred pain and juvenile idiopathic arthritis should be considered at any age. But other conditions are more likely in different age groups.
Preschool: toddler’s fracture, missed developmental dysplasia of the hip, neuroblastoma, acute lymphoblastic leukaemia.
Four to 10 years: transient synovitis, Perthes’ disease, acute lymphoblastic leukaemia.
11 to 16 years: anterior knee pain, slipped upper femoral epiphysis, primary bone tumours.
3. Do not attribute limp to growing pains
Growing pains can occur in children between three and 12 years and importantly do not cause daytime symptoms (including limp), do not affect daily activities, are always symmetrical, and are not limited to joints - these symptoms are red flags.
4. A feverish child with a limp needs same-day assessment
Most paediatricians prefer that feverish children with a limp be referred same-day to exclude septic arthritis and osteomyelitis - especially where there is complete non-weight bearing, refusal to move the limb or severe pain. Even if a GP is considering doing X-rays and bloods followed by observation, we recommend referral anyway - these children will then be in the system if features of septic arthritis appear.
Immunocompromised children may not display typical features of sepsis so careful assessment is crucial. Also consider urgent assessment if a child is systemically unwell, under two years, non-weight bearing, or if there is concern about non-accidental injury (NAI). Never ignore red flags for malignancy or sepsis:
- systemic upset
- non-remitting pain
- night pain
- weight loss
- localised bone pain
- night sweats
- pallor
- unexplained bruising
- fever
- lymphadenopathy
- hepatosplenomegaly.
5. Look for a history of trauma
It is important to consider trauma, especially in younger ambulant children from whom the history may not be forthcoming. But trauma is common and often a swollen joint is only noticed after a coincidental injury. Consider the mechanism of injury – does it sound significant enough to cause a limp, or is the trauma a red herring?
6. Think beyond the hip as a cause of limp
The history in small children can be vague and history alone has been shown to be poor at localising pathology to a particular joint or even limb.2 All joints should be screened in children with a limp. A quick and simple musculoskeletal examination called pGALS - paediatric gait, arms, legs and spine examination - can help identify abnormal joints which can then be more closely examined using a “look, feel, move” approach.3
It will also help to identify joint pathology elsewhere which may otherwise be missed. Limp can also be a presentation of non-musculoskeletal problems. It is important to consider the possibility of referred pain from the abdomen (e.g. urine infection, hernia, appendicitis), chest (pneumonia), testes (torsion) or the spine.
7. Insidious onset limp – with worsening pain on activity – should prompt you to think of Perthes’ disease
Perthes’ disease is an avascular necrosis of the femoral head and can be bilateral. It is most common in boys between four and eight years old but can also occur in girls. Children present with insidious onset limp or pain which may be referred to the thigh or knee and is worse with activity. Children may be non-weight bearing with an acute or chronic presentation. Examination of the hip may reveal limited abduction and internal rotation, and prompt orthopaedic review is essential.
8. Consider non-accidental injury if the history doesn’t fit what you’re seeing
Consider NAI, particularly in younger children with delayed presentation or if the history does not fit with the presentation or child’s developmental stage. Other red flags for NAI include unkempt appearance and previous or multiple injuries. Concerns require urgent assessment and should trigger local safeguarding policies.
9. Consider slipped upper femoral epiphysis in overweight boys over 10
Slipped upper femoral epiphysis is most common in overweight boys over the age of 10 but can also occur in tall, thin teenagers who have recently undergone a growth spurt. An acute epiphyseal slip is painful but a chronic slip is more common and symptoms tend to be indolent. Between 25% and 40% of cases are bilateral. Pain may be felt in the hip or referred to the knee, and is made worse by running and jumping. Trendelenburg gait may be apparent. Diagnosis relies on anteroposterior and ‘frog lateral’ radiographs of both hips, and diagnostic delay can result in much worse outcomes.
10. Juvenile idiopathic arthritis presents very differently to adult rheumatoid arthritis
JIA is defined as joint swelling for more than six weeks, presenting before the age of 16 in the absence of other causes. There is a risk of chronic uveitis which is usually asymptomatic and which - if not detected and treated - can result in visual loss. Presentation is variable; pain may not be a prominent verbalised feature, especially in the very young. Parents may notice a limp or refusal to stand, especially in the morning or after periods of inactivity, due to joint stiffness. On probing, parents may report a change in mood or activities (such as returning to bottom shuffling). Joint swelling may be subtle, especially in bilateral disease or in a chubby toddler. Even if musculoskeletal examination is inconclusive, refer if the history is suggestive of JIA.4
There are no diagnostic tests for JIA – investigations may be normal. Don’t delay referral while waiting for results.
Professor Helen Foster is a consultant paediatric rheumatologist, Dr Hannah Dean is a GP registrar, Dr Eve Smith is a clinical research associate in paediatric rheumatology, all at Great North Children’s Hospital, Newcastle-upon-Tyne. Dr Sharmila Jandial, consultant paediatric rheumatologist, also contributed to this article.
This article was produced with the British Society for Paediatric and Adolescent Rheumatology. Membership is open to healthcare professionals involved in the care of children and adolescents by paediatric rheumatology departments. BSPAR aims to improve provision and quality of healthcare for patients with rheumatic disease in childhood and adolescence, supporting clinical care, research, education and training.
References
1 Smith E, Anderson M, Foster H. The child with a limp: a symptom and not a diagnosis. Archives of Disease in Childhood Education and Practice Edition 2012; 97: 185-93
2 Goff I, Rowan A, Bateman BJ et al. Poor sensitivity of musculoskeletal history in children. Arch Dis Child 2012 Jul;97(7):
644-6
3 Foster HE, Kay LJ, Friswell M, Coady D, Myers A. Musculoskeletal screening examination (pGALS) for school-age children based on the adult GALS screen. Arthritis and Rheumatism 2006 Oct 15;55(5):709-16
4 Jandial S, Myers A, Wise E, Foster HE. Doctors likely to encounter children with musculoskeletal complaints have low confidence in their clinical skills. J Pediatrics 1999; 154(2): 267-71
Further reading
To watch the pGALS video and get further information, go to Arthritis Research UK’s education pages at arthritisresearch.uk.org
