I have had a few interesting cases recently regarding the child presenting with a limp or painful leg. I thought I would put together a small kid size post on what goes through my mind with a limping child,

I like to use the RCH limping child guidelines and also DFTB website has a great post by Andy Tagg (ED consultant at Sunshine) regarding the child with a limp (April 2020). If you have not heard about either of these websites, don’t worry, but please use them as a great resource for all things Paediatric Emergency.

Case .

 ‘18mnth with 1 week of limping on his right leg, febrile and worsening limp despite regular analgesia. No Trauma. Starting to wake at night with pain. Nil PMH, NKDA and otherwise well.’

This is how this presentation reads in my head:  18mnth male with 1 week of limping on his right leg, febrile and worsening limp despite regular analgesia. No Trauma. Starting to wake at night with pain. Nil PMH, NKDA and otherwise well.

Red flags for limping are:-

1. Duration >7days ‘why is it not better? Why have they presented late?’
2. Severe localising joint pain ‘worry about septic arthritis’
3. Change to bowel or bladder function ‘spinal cord involvement, myositis’
4. Night pain ‘infection, malignancy, trauma’
5. Systemic symptoms fever or night sweats, rash ‘Infection, malignancy’
6. Petechia/purpura ‘HSP, malignancy, haematological’
7. Focal neurological signs ‘myositis, discitis, ADEM’

Back to my case. After a pretty normal exam and a child with a definite limp but no localising signs, I decide on two things:

1. An xray to exclude trauma, and I went for hip and femur, as no amount of palpation to below the knee could elicit any complaint.  
2. A bedside hip US. I say this with caution because this cannot diagnose transient synovitis or exclude septic arthritis. It does give you this information ‘ Mr/Madam orthopaedic surgeon there is fluid in the hip joint, could you lend your opinion on whether it needs to be sampled for possible septic arthritis’. Also if there is no joint effusion it helps me to think harder about another diagnosis. 

Xray’s were negative for trauma and there was no effusion in either hip joint.  

At this point it was time to take some bloods, and I am not talking about the ER style lets order everything under the sun including the serum bilirhubarb. I am talking about I know what I want to see come back normal or not

1. Raised CRP/ESR and inflammatory markers, then this kid is coming in under the lovely bone doctors until we know it is not osteomyelitis or septic arthritis. 
2. Normal bloods and I am tossing up between orthopaedics and paediatrics about an admission and further detailed imaging (MRI, bone scan etc). This is because of the already identified red flags. 
3. Abnormal FBC and blood film and I am talking to paediatrics about a likely new presentation leukaemia.

The bloods results for this patient were CRP 26, ESR 51, Hb 91, WCC 1.2, Neut 0.24, PLTs 24, with blasts on the blood film. 

Diagnosis – Leukaemia. 

Whereas most of these presentations in the 0-4 yr age group will end up being transient synovitis, toddlers’ fracture or minor trauma, every now and then in ED we will diagnose something a little different and not as common. 

It was a timely reminder to me about good clinical examination, history and appropriate tests.

Below are some tables and management diagrams from the RCH guidelines which help to summarise a sensible approach. 

Regards

Jeremy (Friend) 

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Jezfriend