Is applying insulin directly to a diabetic foot wound an effective treatment for wound healing in a patient with diabetes mellitus (DM) and a foot wound?

Do Not Apply Insulin Directly to Diabetic Foot Wounds

Topical insulin should not be used as a dressing or treatment for diabetic foot ulcers, as there is no evidence supporting its efficacy and it falls under the category of "other pharmacological agents" that are strongly contraindicated by current guidelines. 1

Evidence-Based Contraindication

The International Working Group on the Diabetic Foot (IWGDF) 2023 guidelines provide a strong recommendation against using "other pharmacological agents to improve wound healing outcomes over standard of care" (Strong; Low certainty). 1 Topical insulin is not mentioned as an approved intervention in any current guideline and would be classified under this contraindicated category. 2

The IWGDF systematically reviewed all randomized controlled trials for wound healing interventions and found no evidence supporting topical pharmacological agents beyond standard wound care. 1

What You Should Use Instead

Standard Wound Care Protocol

Sharp debridement is the cornerstone of treatment - remove all necrotic tissue, slough, and surrounding callus at each visit based on clinical need. 1, 3, 4

Select dressings based on wound characteristics only: 1, 5

• Hydrogels or hydrocolloids for dry or minimally exudative wounds 1, 3
• Alginates or foams for exudative wounds 1, 3
• Avoid antimicrobial dressings unless treating active infection (not for healing acceleration) 1, 2

Mandatory offloading - total contact cast for plantar ulcers or non-removable knee-high devices to eliminate pressure. 3, 4

Vascular assessment - check pedal pulses and ankle-brachial index immediately; obtain urgent vascular consultation if ABI <0.5 or ankle pressure <50 mmHg. 3, 4

Optimize glycemic control - hyperglycemia directly impairs wound healing through multiple mechanisms including decreased oxygenation and impaired immune function. 4, 6

Additional Contraindicated Interventions to Avoid

The IWGDF provides strong recommendations against numerous other topical agents that clinicians sometimes consider: 1, 2

• No topical antiseptics or antimicrobial dressings for healing (Strong; Moderate certainty) 1, 2
• No honey or bee products (Strong; Low certainty) 1, 2
• No collagen or alginate dressings (Strong; Low certainty) 1, 2
• No topical phenytoin (Strong; Low certainty) 1, 2
• No herbal remedies (Strong; Low certainty) 1, 2
• No vitamins or trace element supplements topically (Strong; Low certainty) 1, 2

When Standard Care Fails

Only after optimizing all standard care components for at least 2 weeks should you consider adjunctive therapies: 1

Conditionally recommended options (only if resources exist): 1

• Sucrose-octasulfate impregnated dressing for non-infected neuro-ischemic ulcers (Conditional; Moderate certainty) 1
• Autologous leucocyte, platelet, and fibrin patch (Conditional; Moderate certainty) 1
• Hyperbaric oxygen for neuro-ischemic ulcers where standard care failed (Conditional; Low certainty) 1
• Negative pressure wound therapy for post-surgical wounds only (Conditional; Low certainty) 1

Critical Pitfall to Avoid

The most common error is using advanced or experimental therapies before optimizing the fundamentals. 2 Ensure adequate sharp debridement, complete offloading, appropriate basic dressings, vascular assessment with revascularization if needed, infection control with systemic antibiotics when indicated, and tight glycemic control before considering any adjunctive intervention. 2, 3, 4