What is the appropriate management for a diabetic patient with new‑onset numbness of the right hallux, a lateral callus, and who is not currently taking gabapentin?

Management of Diabetic Neuropathy with Lateral Hallux Callus

This patient requires immediate callus debridement by a trained healthcare professional and initiation of first-line neuropathic pain medication, with gabapentin being an appropriate choice given the patient's non-adherence history. 1

Immediate Foot Assessment and Risk Stratification

Examine the foot with shoes and socks removed to assess for pre-ulcerative signs and infection. 1, 2

• Check for temperature difference between feet using palpation or infrared thermometry—a difference >2°C suggests active Charcot foot, which requires urgent offloading. 2
• Assess for infection by documenting signs of inflammation: erythema, warmth, swelling, tenderness, pain, or purulent discharge—if erythema extends >2 cm around any lesion, this indicates moderate infection requiring broad-spectrum antibiotics. 2
• Test for loss of protective sensation using a 10-g Semmes-Weinstein monofilament at multiple sites on each foot, plus at least one additional test (128-Hz tuning fork for vibration, pinprick sensation, or ankle reflexes). 2
• Palpate dorsalis pedis and posterior tibial pulses bilaterally and ask specifically about claudication, leg fatigue, or decreased walking speed to assess for peripheral arterial disease. 2

Callus Management

The lateral hallux callus must be professionally debrided with a scalpel by a foot care specialist or trained healthcare professional—this is essential to prevent ulceration. 1

• Callus formation under areas of increased pressure is a pre-ulcerative lesion that strongly predicts future ulceration and requires treatment to help prevent foot ulcers. 1, 3
• Do not allow the patient to self-treat the callus, especially given the presence of neuropathy. 4
• Consider prescribing orthotic interventions such as toe silicone or semi-rigid orthotic devices to help reduce excess callus on the toe. 1
• If foot deformity is present that significantly increases pressure, consider prescribing extra-depth shoes, custom-made footwear, or custom-made insoles. 1

Neuropathic Pain Treatment

Since the patient reports non-adherence to gabapentin, restart gabapentin with proper education about titration and expected benefits, or consider alternative first-line agents. 1

First-Line Medication Options (Choose One Based on Comorbidities):

• Gabapentin: Start 300 mg at bedtime, titrate to 300-1200 mg three times daily (maximum 3600 mg/day). Gabapentin is effective for diabetic peripheral neuropathy pain relief and improves sleep interference, mood, and quality of life. 1, 5, 6
• Pregabalin: 100 mg three times daily (if cost is not prohibitive). Pregabalin has superior adverse event profile compared to gabapentin. 1
• Duloxetine: 60-120 mg daily. This SNRI is effective and also improves quality of life. 1
• Amitriptyline: 10-75 mg at bedtime (if no contraindications such as glaucoma, orthostatic hypotension, cardiovascular disease, or fall risk). 1

Important Contraindications to Consider:

• Avoid tricyclic antidepressants (TCAs) if the patient has glaucoma, orthostatic hypotension, cardiovascular disease, or unsteadiness/falls. 1
• Avoid duloxetine if hepatic disease is present. 1
• Use gabapentin or pregabalin cautiously if edema is present. 1
• Be aware that gabapentin may cause mild hyperglycemia in some diabetic patients, requiring closer glucose monitoring. 7

Common Pitfall:

The most common adverse effects of gabapentin are dizziness (24%) and somnolence (23%), which can be minimized by slow titration starting at bedtime dosing. 5 Educate the patient that these effects typically diminish with continued use and that pain relief may take 1-2 weeks to manifest. 5, 6

Preventive Education and Follow-Up

Provide structured foot care education immediately, as this patient is at high risk (IWGDF risk 2-3 due to neuropathy and pre-ulcerative callus). 1, 2

• Instruct daily foot inspection including between all toes, using a mirror or caregiver assistance if needed. 2
• Wash feet daily with lukewarm water (<37°C), dry carefully especially between toes. 2
• Apply emollients to dry skin but NOT between toes to prevent maceration. 2
• Never walk barefoot, in socks only, or in thin-soled slippers—even indoors. 2
• Prescribe properly fitting therapeutic footwear with adequate depth and cushioning. 2
• Schedule follow-up every 1-3 months given high-risk status (neuropathy with pre-ulcerative lesion). 1, 2

Optimize Glycemic Control

Aggressive glycemic control is the only treatment that can slow progression of underlying nerve damage, though it will not reverse neuronal loss. 1 Review current diabetes management and intensify if HbA1c is not at goal. 1