What is the best treatment approach for a patient with a callus, potentially complicated by impaired glucose regulation (diabetes) and poor circulation?

Treatment of Callus in Patients with Diabetes and Poor Circulation

All excess callus must be removed by sharp debridement performed by a trained healthcare professional, as this is the gold standard treatment that reduces plantar pressure and removes bacterial reservoirs that can lead to ulceration. 1, 2

Immediate Assessment Before Treatment

Before any callus debridement, vascular status must be evaluated:

• Palpate dorsalis pedis and posterior tibial pulses - if both are palpable, arterial supply is adequate and sharp debridement can proceed safely 2
• Measure ankle-brachial index (ABI) if pulses are absent or diminished - do not perform aggressive sharp debridement if ABI <0.5, ankle pressure <50 mmHg, or signs of severe ischemia are present without vascular surgery consultation 2, 3
• Inspect for underlying ulceration - use a sterile metal probe after debridement to assess for hidden ulcers or bone involvement 2

Sharp Debridement Technique (First-Line Treatment)

Sharp debridement using scalpel, scissors, or tissue nippers is the most definitive, controllable, and cost-effective method available and should be performed as follows: 2, 3

• Remove all hyperkeratotic tissue (callus) down to viable tissue to reduce pressure at callused sites and eliminate colonizing bacteria 2
• Warn patients beforehand that bleeding is expected and the wound will appear larger after debridement when its full extent is exposed 2, 3
• Repeat debridement as often as needed if nonviable tissue continues to form 2
• Can usually be performed without anesthesia in neuropathic patients, making it accessible as a bedside procedure 3

Critical Pitfall to Avoid

Do not delay callus removal - the presence of callus is associated with 44% longer healing times per log10 increase in bacterial count and significantly increases ulceration risk 2, 4

Post-Debridement Wound Care

After sharp debridement, proper wound management is essential:

• Clean with clean water or saline only - avoid cytotoxic agents like hydrogen peroxide or povidone-iodine 2
• Apply sterile, inert dressings - do not use antimicrobial dressings with the goal of improving healing, as they provide no benefit 2, 3
• Maintain a moist (not wet) wound environment using appropriate dressings based on exudate level 2

Addressing Underlying Mechanical Causes

The underlying cause of callus formation must be addressed, which is typically abnormal pressure or ill-fitting footwear: 2

For Patients at Risk (IWGDF Risk 1-3):

• Prescribe therapeutic footwear with demonstrated plantar pressure-relieving effect for those with healed plantar ulcers 1
• Consider extra-depth shoes, custom-made footwear, or custom-made insoles for patients with foot deformities that significantly increase pressure 1
• Consider orthotic interventions such as toe silicone or rigid orthotic devices to help reduce excess callus, particularly on toes 1
• Ensure proper footwear fit - shoes should be 1-2 cm longer than the foot, with width equal to the metatarsal phalangeal joints 1

Surgical Considerations for Refractory Cases:

For non-rigid hammertoe with excess callus or pre-ulcerative lesions that fail non-surgical treatment, consider digital flexor tendon tenotomy to normalize foot structure and prevent ulceration 1

Integrated Preventive Care Strategy

Provide integrated foot care for patients at moderate or high risk (IWGDF risk 2-3) including: 1

• Professional foot care every 1-3 months for high-risk patients, every 3-6 months for moderate-risk patients 1
• Daily foot inspection by patient using palpation or visual inspection with a mirror 1
• Proper foot hygiene including daily inspection of shoe interiors, avoiding barefoot walking, using lubricating creams for dry skin (but not between toes), and cutting nails straight across 1
• Immediate reporting of any blisters, cuts, scratches, or sores to healthcare provider 1

Topical Keratolytic Agents (Limited Role)

Salicylic acid preparations may be used as adjunctive therapy but have significant limitations:

• Apply to affected area at night after washing, wash off in morning 5
• Avoid prolonged use over large areas especially in patients with renal or hepatic impairment due to risk of salicylism 5
• Do not use in children under 12 or with varicella/influenza due to Reye's syndrome risk 5
• Sharp debridement remains superior to chemical keratolytics for callus removal 2

Follow-Up and Monitoring

• Re-evaluate daily if hospitalized, or in 3-5 days if outpatient, or sooner if worsening 3
• Inspect feet at every visit for patients with evidence of sensory loss or prior ulceration 1
• Monitor for signs of infection including increased drainage, erythema, or systemic symptoms requiring systemic antibiotics 3