How to differentiate and treat scurvy versus osteomyelitis in a child?

Differentiating and Treating Scurvy vs Osteomyelitis in Children

Scurvy is frequently misdiagnosed as osteomyelitis in children, but can be distinguished by careful dietary history, characteristic radiographic findings (periosteal elevation without bone destruction), and the presence of dermatologic signs (petechiae, gingival bleeding), with vitamin C therapy providing rapid clinical improvement within days to weeks. 1, 2, 3

Key Clinical Distinctions

History and Risk Factors

• Scurvy occurs predominantly in children with restrictive diets, including those with autism spectrum disorder, cerebral palsy, or severe psychomotor retardation who have chronic vitamin C deficiency 2, 3, 4
• Osteomyelitis typically presents in children <5 years of age (50% of cases), often with a history of recent trauma, and is caused by hematogenous bacterial seeding, most commonly Staphylococcus aureus 5, 6
• Obtain detailed dietary history focusing specifically on vitamin C intake (fresh fruits, vegetables) - this is the critical distinguishing feature that is often overlooked 3, 7

Clinical Presentation Overlap

Both conditions present with:

• Lower extremity pain, limping, or refusal to walk 1, 2, 3
• Swelling and tenderness over affected bones 1, 2
• However, only ~50% of osteomyelitis cases present with the classic triad of fever, pain, and diminished mobility 8, 6

Distinguishing Clinical Features

Scurvy-specific findings:

• Petechiae and perifollicular hemorrhages (dermatologic manifestations) 2, 3
• Gingival bleeding and swelling 2, 3
• Anorexia, irritability, failure to thrive 3
• Symptoms typically bilateral and symmetric around joints 1

Osteomyelitis-specific findings:

• Fever more common (though not always present) 8, 6
• Typically unilateral presentation 5
• Localized warmth and erythema over affected area 5

Diagnostic Algorithm

Step 1: Initial Imaging - Plain Radiographs

• Obtain radiographs first in all cases 5, 8

Scurvy radiographic findings (pathognomonic):

• Periosteal elevation with subperiosteal hemorrhage 1, 2
• Ground-glass osteopenia 1
• Wimberger ring sign (dense metaphyseal line) 1
• Crucially: NO bone destruction or lytic lesions 1

Osteomyelitis radiographic findings:

• Often normal in acute phase (requires 10-14 days for changes to appear) 8, 6
• Bone destruction requires >30% osseous matrix loss to be visible 8
• Periosteal reaction may be present but associated with bone destruction 5

Step 2: Advanced Imaging When Diagnosis Unclear

If osteomyelitis suspected and radiographs normal or equivocal:

• MRI is the diagnostic modality of choice with 82-100% sensitivity and 75-96% specificity 9, 5
• MRI findings in osteomyelitis: decreased T1-weighted bone marrow signal, increased signal on fluid-sensitive sequences, and subperiosteal fluid (distinguishing feature) 9, 5
• Contrast-enhanced MRI improves detection of abscesses 9

If scurvy suspected:

• Ultrasound can demonstrate periosteal cleavage and subperiosteal hematomas (not abscesses) 4
• MRI may show extensive blood clot in periosteum without signs of infection 1

Step 3: Laboratory Evaluation

For suspected osteomyelitis:

• Blood cultures before antibiotics 5
• Image-guided aspiration of affected joint or bone for Gram stain, culture, cell count 5
• Elevated inflammatory markers (ESR, CRP) expected 5

For suspected scurvy:

• Serum vitamin C level is gold standard (though often unavailable) 1
• Normal inflammatory markers despite clinical presentation 1, 3
• Consider therapeutic trial of vitamin C if clinical and radiographic findings suggestive 1, 7

Critical Pitfalls to Avoid

Common Misdiagnosis Scenario

• Multiple case reports document children with scurvy undergoing unnecessary surgery for presumed osteomyelitis, with intraoperative findings revealing extensive blood clots and subperiosteal hematomas instead of purulent material 1, 2, 4
• Scurvy is frequently mistaken for osteomyelitis, septic arthritis, bone tumors, leukemia, and bleeding disorders 3, 7

When to Suspect Scurvy Despite Initial Osteomyelitis Diagnosis

• No clinical improvement after 2 weeks of appropriate IV antibiotics 1
• Intraoperative findings of blood clots rather than purulent material 1, 2
• Bilateral or symmetric involvement 1
• Presence of skin findings (petechiae, gingival bleeding) 2, 3
• History of restrictive diet in neurologically impaired child 2, 3, 4

Treatment Approach

For Confirmed Scurvy

• Ascorbic acid 400 mg/day orally (or IV if oral not possible) 10, 4
• Clinical improvement occurs within days to 2 weeks 1, 4, 7
• Radiographic improvement follows over 2-12 months 1
• For pediatric patients ≥5 months: follow RDA dosing guidelines 10
• Use caution in patients <2 years due to higher risk of oxalate nephropathy from decreased glomerular filtration 10

For Confirmed Osteomyelitis

• Urgent orthopedic consultation, as septic arthritis (which occurs concurrently in >50% of cases) is an orthopedic emergency 8, 6
• IV antibiotics targeting S. aureus 5, 6
• Consider Kingella kingae in children <4 years 8, 6
• Surgical drainage if abscess present 5

When Diagnosis Remains Uncertain

• If strong clinical suspicion for scurvy based on dietary history and radiographic findings, initiate vitamin C therapy immediately 7
• This therapeutic trial prevents unnecessary invasive procedures and provides rapid diagnostic confirmation if symptoms resolve 1, 7
• Delayed diagnosis of osteomyelitis results in premature physeal arrest or permanent joint damage, so if infectious etiology cannot be excluded, empiric antibiotics should be started while awaiting culture results 8, 6