Limp is an abnormal walking pattern taking into consideration the child's development.
Limp is a defined as 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).
Key points to remember about limp:
- Limp is a symptom and not a diagnosis.
- Urgent referral is warranted: for non-weight bearing, unwell or febrile, or very young (<3 years) or immunosuppressed.
- 'Red flags' (e.g., high fever, weight loss, night pain, lethargy) suggest infection or malignancy.
- Trauma can cause limp but note 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 determines the likely cause, helps identify red flags (history and 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). 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 it is important to assess other joints and consider extra-articular causes (e.g., urine infection, hernia, testicular torsion).
- Be aware of motor milestones. With delayed milestones consider inherited myopathies. 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
Key points when assessing a child who is limping:
- 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.
Further information about limp is available - we refer to the Clinical Guidelines from Royal Children's Hospital Melbourne, Australia: