Plain film x-rays in the diagnosis of sickle cell limb pain in children

Background and aims: Children with sickle cell disease (SCD) frequently present with limb pain. Differentials include vaso-occlusive episode (VOE) and osteomyelitis (OM). X-rays expose to radiation but rarely aid in diagnosis. We audited the use of x-ray in investigating children with SCD presenting with limb pain to a South London hospital and analysed whether x-rays aid in diagnosis. Methods: Patients aged 0-18 with SCD were identified using the hospital’s SCD database. Admissions from January 2010 to September 2019 in which limb pain was a documented symptom were included. Results: Of 342 patients investigated, there were 188 admissions with limb pain. Diagnoses at discharge were: 174 VOE, 4 OM, and 7 others. 44 (25%) of those with VOE had limb x-rays, compared with 3 (75%) of those with OM. Of those x-rayed, 11 with VOE and all with OM had a subsequent MRI. None of the x-rays assisted in confirming the diagnosis or change management. Of the VOE patients, more of those that were x-rayed had swelling (48% vs 8%, p=<0.0001), and fevers (57% vs 37%, p=0.021), and peak CRP was higher (109 vs 75, p=0.044). Conclusions: X-rays were frequently used to investigate children with SCD. Limb swelling, fevers and higher CRP, features potentially suggestive of OM, were more common in those that were x-rayed. X-rays did not aid in distinguishing VOE and OM or change management.