Child with prolonged leg pain and bruising
Authors: Bailey Emma , Ali Alaa , Kagalwala Fatima 
Published: March 2020

A 12-year-old boy was admitted to the paediatric ward with a 4-month
history of worsening pain and bruising to his legs, which had resulted
in a progressive reduction in his mobility. He initially had had
difficulty weight bearing, which had then progressed further making him
wheelchair bound. On examination, there was extensive bruising (figure
1) to his oedematous legs, worse on his right leg compared with his
left. His background of autism and 15q13.3 deletion, along with maternal
learning difficulties, made deciphering a clear history difficult.
However, there was no account of trauma, and he had been afebrile
throughout his illness. He had though lost 6 kg in weight but remained
clinically stable. He was admitted to the ward for further
assessment.

Figure 1

Clinical photograph showing bilateral bruises and swellings
of the legs.

Question 1
What differentials should be considered?

Question 2
What investigation is more likely to suggest the diagnosis?

Baseline bloods: full blood count—including platelets,
albumin and coagulation.

Extended bloods: vasculitis screen, erythrocyte
Sedimentation Rate, endocrinopathies and iron studies.

Doppler ultrasound calves.

X-ray legs/hips.

MRI tibia and fibula.

Initial investigations showed a haemoglobin of 67 g/L, with mean
cell volume of 76 fL. Platelet count and white cell counts, including
differentials, were all within range. Infection markers, renal function
tests, liver function tests and clotting screens were all normal. Leg
X-rays were performed and showed no obvious fracture. However, there
were some bone changes noted that had not been present 4 months prior
during a previous presentation.
USS Doppler of his calves were done, excluding deep vein
thrombosis.
Further investigations as to possible causes of his anaemia and
other symptoms were then started, including rheumatology screens,
haemaglobinpathy screens, endocrinopathies and viral screens. These
results, along with vitamin D levels and bone profile, all came back
normal. However, iron studies showed low serum iron and transferrin
saturation. He had been empirically treated with a course of intravenous
ceftriaxone on admission, which was subsequently stopped in view of lack
of any evidence (clinically, radiologically or otherwise) of
osteomyelitis, septic arthritis or other infective state.
His behaviour on the ward, however, quickly raised some questions;
in particular his detailed dietary history showed a very limited range,
consisting solely of chicken nuggets, chips and pizza.
Therefore, while awaiting results of any definite ‘cause’ of his
immobility, his care was managed holistically. He was started on oral
iron therapy and a strict dietary plan, including Ensure supplements.
Physiotherapy was started, and various methods to encourage him to
mobilise were commenced. His reluctance to engage with these
'treatments' initially caused problems, however through negotiation of
‘iPad time’ with compliance, they were slowly built up. Along with other
professionals, the safeguarding team were also involved in his care at
this point.
Though a clear diagnosis was still unclear, he clinically improved.
Oedema of his legs and bruising reduced, and he was able to mobilise a
few steps further each day on the ward.

Question 3
What is the most likely action that would help confirm the
diagnosis?

Bone marrow biopsy.

Full-body MRI.

Complete nutritional history.

Referral to tertiary orthopaedic centre.

Answers can be found on page 02.