A 10-year-old boy with a history of type 1 diabetes mellitus presented to the emergency department (ED) with fevers for five days. Symptoms began with temperatures as high as 104⁰F with ketones in the urine noted on a home test. The patient did not have any associated symptoms. His mom stated that he had a limp that began after a dance rehearsal a few days ago, though no trauma was reported, and had since improved. The patient’s vaccination record was up to date. On exam, the patient was noted to have a slightly red, minimally tender, flat lesion of the left ankle which was not warm to touch (Image 1). His gait was normal. He had a fever but otherwise the rest of the vital signs were normal. Laboratory tests and an X-ray of the ankle were obtained. Results included: WBC of 6.4 x 10³ /µL, CRP of 2.5 mg/L (ref <4.90 mg/L), and procalcitonin of 2.24 ng/mL (ref 0.00-0.50 ng/mL). The chemistry panel was normal with blood glucose 81 mg/dL and no evidence of metabolic acidosis. The ankle X-ray showed soft tissue swelling without acute osseous abnormality. Blood cultures were sent. The patient was presumed to have cellulitis given skin discoloration and swelling on X-ray. He was given ceftriaxone in the ED but developed a rash,and was discharged on doxycycline.

Image 1. Note the subtle ankle rash on left anterolateral ankle. (Click to enlarge.)

The following day, blood cultures were positive for Staphylococcus aureus (MSSA). The patient was called to return and subsequently admitted for bacteremia. An MRI of the ankle was obtained, which revealed osteomyelitis with a small amount (1 mL) of fluid along the anterior distal tibia. Patient was subsequently taken to the operating room with orthopedics for drainage and decompression. Following this, he continued to improve with IV antibiotics and was subsequently discharged on a four-week course of cefazolin per the request of the consulting infectious disease team. Noting the patient’s adverse reaction to ceftriaxone, the patient was initially monitored when given cefazolin as there was potential for cross reactivity, but he tolerated it well without reaction.

Image 2. Click to enlarge.

Osteomyelitis is one of the most prevalent musculoskeletal infections plaguing pediatric populations.¹ Pathogenically it can develop by hematologic spread or via direct inoculation with significant penetrating trauma or surgery.¹ The most common culprit is Staphylococcus aureus, as in our case. Presentation of osteomyelitis is varied and dependent on the extent of the infection. On one end of the spectrum, it can be a localized infection present on a single metaphysis free of associated symptoms. The other extreme is severe multifocal infection accompanied by septic shock.²

Image 3. Click to enlarge.

Our patient was misdiagnosed initially but, fortunately, a positive blood culture helped identify the diagnosis, and the patient was treated appropriately prior to development of permanent sequelae. The diagnosis of osteomyelitis is often difficult as it presents subclinically in the early stages and is relatively rare. Fever and pain are the most common presenting symptoms of osteomyelitis and can manifest as difficulty bearing weight or reduced use of the affected limb in pediatric patients.² In our case the patient did have fever and a limp which was presumed secondary to sprain from the preceding dance lesson. A minimal skin abnormality consistent with inflammation was present, likely indicating the patient had an indolent infection. The use of inflammatory markers can guide the treatment plan, and an X-ray might show evidence of osteomyelitis. ³ Those were inconclusive on our patient and an MRI on initial presentation would have been ideal for diagnosis.³

The prevalence of osteomyelitis in children within developed nations is 13 per 100,000, however it is higher among those with diabetes.^4,5 Research evaluating the intersectionality of type 1 diabetes mellitus and osteomyelitis in pediatric patients is extremely limited, therefore calculating an exact prevalence rate is difficult. It has been determined that patients with diabetes have a 1.5-4.5 times greater risk of infection than the general population.⁵ This makes the diagnosis a pertinent consideration when a diabetic patient presents with fever from an unclear source.

References

1. Walter N, Bärtl S, Alt V, Rupp M. The epidemiology of osteomyelitis in children. Children (Basel). 2021;8(11):1000. doi:10.3390/children8111000.
2. Woods CR, Bradley JS, Chatterjee A, et al. Clinical practice guideline by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America: 2021 guideline on diagnosis and management of acute hematogenous osteomyelitis in pediatrics. J Pediatric Infect Dis Soc. 2021;10(8):801-844. doi:10.1093/jpids/piab027.
3. Hackenberg RK, Schmitt-Sánchez F, Endler C, et al. Value of Diagnostic Tools in the Diagnosis of Osteomyelitis: Pilot Study to Establish an Osteomyelitis Score. J Clin Med. 2023;12(9):3057. Published April 23, 2023.. doi:10.3390/jcm12093057.
4. Momodu II, Savaliya V. Osteomyelitis. In: StatPearls. StatPearls Publishing; 2023. Accessed September 19, 2025. https://www.ncbi.nlm.nih.gov/books/NBK532250/.
5. Holt RIG, Cockram CS, Ma RCW, Luk AOY. Diabetes and infection: Review of the epidemiology, mechanisms and principles of treatment. Diabetologia. 2024;67:1168-1180. doi:10.1007/s00125-024-06102-x.