What is the appropriate workup for an 18-year-old female presenting with numbness and tingling in both feet, mainly the toes, lasting over a week after wearing high heel shoes?

Workup for Bilateral Foot Numbness and Tingling After High Heel Use

This is most likely a compressive neuropathy from prolonged high heel use, but you must rule out systemic causes of peripheral neuropathy before attributing symptoms solely to footwear.

Initial Clinical Assessment

History Taking

• Duration and pattern of symptoms: Determine if numbness/tingling is constant or intermittent, and whether it has improved since discontinuing high heel use 1, 2
• Specific symptom characteristics: Ask about burning sensations, sharp pain, or purely sensory changes (numbness/tingling suggests small fiber involvement) 3
• Footwear details: Document heel height, duration of wear per day, frequency of use, and type of shoe support 4, 5
• Associated symptoms: Screen for pain in other body regions (shoulders, upper back, lower extremities), balance problems, or weakness 6
• Risk factors for systemic neuropathy: Diabetes history, alcohol use, vitamin deficiencies (B12, folate), family history of neuropathy, medications (chemotherapy), autoimmune conditions 3

Physical Examination

Perform a comprehensive neurological foot examination including 3:

• Small fiber function: Pinprick sensation and temperature sensation testing in both feet, particularly the toes 3
• Large fiber function: Vibration testing with 128-Hz tuning fork, assessment of ankle reflexes 3
• Protective sensation: 10-g monofilament testing at multiple plantar sites 3
• Vascular assessment: Palpate dorsalis pedis and posterior tibial pulses, assess capillary refill time 3, 7
• Structural examination: Inspect for foot deformities, calluses, or pressure points that may indicate altered biomechanics from high heel use 3, 1
• Tarsal tunnel assessment: Palpate along the posterior tibial nerve course behind the medial malleolus; perform Tinel's sign 1, 2

Laboratory Workup

Order the following tests to exclude systemic causes of neuropathy 3:

• Hemoglobin A1c or fasting glucose: Screen for diabetes (the most common cause of peripheral neuropathy in young adults if present) 3
• Vitamin B12 level: Deficiency causes sensory neuropathy 3
• Thyroid function tests: Hypothyroidism can cause neuropathy 3
• Complete blood count: Screen for anemia or hematologic disorders 3
• Comprehensive metabolic panel: Assess renal function and electrolytes 3

Imaging Considerations

Imaging is NOT routinely indicated for this presentation unless specific red flags are present 3, 7:

• Do NOT order routine foot radiographs unless there is history of trauma, inability to bear weight, or point tenderness over bony structures per Ottawa Ankle Rules 3, 7
• Consider MRI without contrast only if symptoms persist beyond 4-6 weeks despite conservative management and laboratory workup is negative, to evaluate for tarsal tunnel syndrome or other compressive neuropathies 7, 2

Electrodiagnostic Testing

Electrophysiological testing (EMG/NCS) is rarely needed 3:

• Reserve for cases where clinical features are atypical, diagnosis remains unclear after initial workup, or symptoms persist beyond 8-12 weeks 3
• Consider referral to neurology if bilateral symptoms suggest systemic polyneuropathy rather than focal compression 3

Clinical Decision Algorithm

If Laboratory Tests Are Normal:

• Diagnosis: Likely mechanical compression neuropathy from high heel use (anterior tarsal tunnel syndrome or digital nerve compression) 1, 2, 4
• Management: Immediate cessation of high heel use, transition to supportive footwear with proper arch support and cushioning, NSAIDs for symptom relief 8, 2
• Expected timeline: Symptoms should improve within 2-4 weeks with footwear modification 8, 2

If Laboratory Tests Show Abnormalities:

• Treat underlying condition (diabetes management, vitamin B12 supplementation, thyroid replacement) 3
• Still recommend footwear modification as high heels can exacerbate underlying neuropathy 4, 6

If Symptoms Persist Beyond 6-8 Weeks:

• Refer to neurology for electrodiagnostic studies 3
• Consider podiatry referral for custom orthotics and biomechanical assessment 3, 8
• Obtain MRI to evaluate for structural causes of nerve compression 7, 2

Critical Pitfalls to Avoid

• Do not assume symptoms are purely mechanical without screening for diabetes: Even in an 18-year-old, type 1 or type 2 diabetes can present with neuropathy 3
• Do not overlook bilateral presentation: While high heels can cause bilateral symptoms, true bilateral peripheral neuropathy more commonly suggests systemic disease 3, 1
• Do not order extensive imaging initially: This is a clinical diagnosis; imaging is low-yield unless red flags are present 3, 7
• Reexamine at 2-4 weeks: If symptoms are not improving with conservative measures, escalate workup rather than continuing to observe 3, 8