Objective: To identify clinical and laboratory features predictive of osteomyelitis in children with sickle cell disease and bony pain.
Design: Patients in the case group and participants in the control group were randomized in a 1:3 ratio.
Setting: The Hospital for Sick Children, Toronto, Ontario, Canada.
Participants: Patients with sickle cell disease and osteomyelitis (case patients) and patients with sickle cell disease and bony, vaso-occlusive crisis (control patients), 18 years or younger.
Main outcome measures: Five characteristics (number of painful sites, white blood cell count, swelling of the affected limb[s], and duration of pain and fever before presentation) at the time of presentation to hospital.
Results: Data were analyzed for 31 cases and 93 controls. Compared with controls, cases had more days of pain (5 vs 2 days; odds ratio [OR], 1.2; 95% confidence interval [CI], 1.1-1.4 days) and fever (1 vs 0 day; 1.7; 1.2-2.4 days) before presentation. Cases were also more likely to have swelling of the affected limb(s) (71% vs 17%; OR, 11.8; 95% CI, 4.6%-30.0%) and fewer painful sites (1 vs 2; 0.7; 0.5-1.0). On laboratory evaluation, cases had higher white blood cell counts (18.6 vs 15.6/microL; OR, 1.1; 95% CI, 1.0-1.1/microL). Multivariate logistic regression showed that the significant predictors of osteomyelitis were duration of fever (OR, 1.8; 95% CI, 1.2-2.6) and pain (1.2; 1.0-1.4) before presentation and swelling of the affected limb (8.4; 3.5-20.0). The risk of osteomyelitis was decreased if more than 1 painful site was present (OR, 0.7; 95% CI, 0.5-1.0).
Conclusion: In the clinical scenario of a child with sickle cell disease presenting with bony pain and swelling affecting a single site, with prolonged fever and pain, the physician should consider closer monitoring and investigations to exclude a diagnosis of osteomyelitis.