What is the significance and management of calluses in a patient with diabetes?

Calluses in Diabetes: Critical Pre-Ulcerative Lesions Requiring Immediate Treatment

Calluses in patients with diabetes are pre-ulcerative warning signs that significantly increase plantar pressure and must be professionally removed to prevent foot ulceration, which carries a 19-34% lifetime risk and is associated with high morbidity and mortality. 1

Why Calluses Are Dangerous in Diabetes

Calluses represent areas of abnormally high mechanical pressure on the foot and are strong independent predictors of future ulceration. 1 The pathophysiology involves:

• Increased plantar pressure: Callus formation indicates focal areas of excessive mechanical stress, particularly beneath metatarsal heads 2, 3
• Shear stress accumulation: These high-pressure areas generate shear forces that ultimately lead to tissue breakdown and ulcer formation beneath the callus 4, 3
• Neuropathy masking injury: Loss of protective sensation (present in 75% of at-risk diabetic patients) prevents patients from feeling the repetitive trauma that calluses cause 5
• Barrier dysfunction: Diabetic patients often have xerosis (dry skin) with impaired barrier function, making callused areas more vulnerable to fissuring and infection 2

Immediate Management Algorithm

Step 1: Professional Callus Removal

• Remove all callus using sharp debridement performed by a trained healthcare professional 1
• This is a strong recommendation despite low-quality direct evidence, because callus removal reduces plantar pressure by 30% or more 1
• Never allow patients to use chemical agents or plasters to self-remove callus 1

Step 2: Risk Stratification Classify the patient using IWGDF risk categories to determine follow-up intensity: 6, 7

• IWGDF Risk 1 (neuropathy alone): Follow every 6 months
• IWGDF Risk 2 (neuropathy + deformity or PAD): Follow every 3-6 months
• IWGDF Risk 3 (history of ulcer/amputation): Follow every 1-3 months

Step 3: Pressure Redistribution

• Prescribe orthotic interventions such as custom-made insoles or rigid orthotic devices to redistribute abnormal foot pressures 1, 4
• For patients with foot deformity or pre-ulcerative lesions (Risk 2-3), consider extra-depth shoes, custom-made footwear, or toe orthoses 1
• Rigid orthoses show significant reduction in callus grade after 12 months of use 4

Step 4: Footwear Education

• Instruct patients never to walk barefoot, in socks only, or in thin-soled slippers whether at home or outside 1, 6, 7
• Ensure properly fitting footwear that accommodates foot shape 1
• Patients must inspect shoes daily for foreign objects before wearing 6

Integrated Prevention Strategy

For all at-risk patients (IWGDF Risk 1-3): 1

• Provide structured education on daily foot inspection and proper foot hygiene 1, 7
• Instruct patients to contact healthcare professionals immediately if callus reappears or any pre-ulcerative signs develop 1
• Consider daily foot skin temperature monitoring for high-risk patients (Risk 2-3) to detect early inflammation 1, 7

For moderate-to-high risk patients (IWGDF Risk 2-3): 1

• Provide integrated foot care including professional foot treatment, therapeutic footwear, and education
• Repeat professional callus removal every 1-3 months for high-risk patients, every 3-6 months for moderate-risk patients 1

Critical Pitfalls to Avoid

• Never dismiss callus as "just dry skin": Callus is a pre-ulcerative lesion requiring immediate professional treatment 1
• Never allow self-treatment: Chemical agents and over-the-counter callus removers can cause chemical burns in neuropathic feet 1
• Never ignore recurrent callus: Recurring callus indicates inadequate pressure relief and requires footwear modification or orthotic prescription 1, 4
• Never forget the ulcer recurrence rate: After healing, 40% of diabetic foot ulcers recur within one year and 65% within three years, making prevention paramount 1, 7

The Bottom Line

Calluses in diabetic patients are not cosmetic issues—they are mechanical warning signs of impending ulceration that require the same urgency as other pre-ulcerative lesions. 1 The combination of professional callus removal, pressure-relieving footwear, and regular monitoring forms the cornerstone of ulcer prevention in this high-risk population. 1