Making a Diagnosis
There are a wide variety of causes of limp, which vary by age, and include red flag conditions. Assessment will include history and examination, blood tests and imaging. These are covered in more detail under the red flag and key conditions. Remember that non-hip and non-musculoskeletal causes of limp can also occur. Be aware of the pitfalls!
- The child may not give any verbal history and this is often obtained from the parent/caregiver.
- The history may not tell you where the problems are (so there is need to examine all joints as part of your general assessment - and to perform, at least, a pGALS assessment).
- Children may not verbalise pain and non-verbal clues are important (e.g., facial expression, withdrawal of a limb).
- Normal musculoskeletal development is important to know as there are normal variants. Furthermore, ranges of joint movement, leg alignment, gait pattern, and motor milestones all change with age. You need to know what is normal to be able to identify what is abnormal.
Indications for urgent (same day) assessment:
- The very young child (under 3 years of age).
- The ill and febrile child.
- The non-weight bearing child.
- The child with painful restricted hip movements.
- The child who is immunosuppressed.
The child with a limp must have a follow up plan, parents should have instructions when to seek medical attention (i.e., 'safety netting') and further assessment is needed for the child who is not recovering, or is intermittently limping.
Before embarking on a series of investigations, especially if these may be invasive or incur delay, then consider referral to paediatric rheumatology. Many children with inflammatory joint or muscle disease have a history of intermittent limp without a clear diagnosis (see Pitfalls) and may have had investigations such as MRI or synovial biopsy that is not warranted.