Limp is an abnormal walking pattern taking into consideration the child's age. Limp is an asymmetric gait which is often, but not always, due to pain. The differential diagnosis is wide and varies with age. Conditions can range from the benign (e.g., splinter in the foot) to the serious (e.g., Juvenile Idiopathic Arthritis), to the life-threatening (e.g., malignancy, sepsis, rheumatic fever or non-accidental injury).
- Limp is a symptom and not a diagnosis.
- Urgent referral is warranted for the child who is non-weight bearing, unwell or febrile, very young (<3 years) or immunosuppressed.
- 'Red flag' features (e.g., high fever, weight loss, night pain, lethargy) suggest infection or malignancy.
- Trauma including non-accidental injury, must be considered but it is noteworthy that children with pathology may be more prone to falling.
- A limp persisting beyond two weeks requires referral to paediatrics, paediatric rheumatology or paediatric orthopaedics (pending local referral pathways).
- Careful clinical assessment will help you to determine the likely cause, help identify red flags in the history and red flags in the examination, and guide further investigations and management.
- Morning stiffness or 'gelling' (stiffness after periods of rest), even if without obvious joint swelling, suggests inflammatory causes such as Juvenile Idiopathic Arthritis (JIA) and urgent referral is warranted.
- It is important to examine all joints and not just the legs. pGALS is useful and guides further detailed examination.
- Many hip pathologies cause limp, but assess other joints and consider extra-articular causes (e.g., urine infection, hernia, testicular torsion).
- With delayed milestones, consider inherited myopathies and with regression of achieved milestones, consider inflammatory disease (joint or muscle).
- Growing pains do NOT cause limp. Be aware of the rules of growing pains
We encourage you to watch a video of a 22 month old girl who is limping. Key points to note:
- Young children may not verbalise pain and non-verbal clues are important (e.g., facial expression, withdrawal of a limb or non-use of a limb).
- You need to observe the whole child and examine all joints as the history may not localise all joint involvement. As a minimum, a pGALS assessment is needed with movements performed passively if the child is young.
- You need to be aware of normal musculoskeletal development and motor milestones to identify what is abnormal.
The photograph shows a short right leg (due to hip disease) resulting in a limp.