What is a foot corn?

Foot Corns: Definition, Causes, and Management

A foot corn is a localized area of thickened skin (hyperkeratosis) that forms in response to chronic excessive pressure or friction on the foot, typically appearing as a hard, painful, cone-shaped lesion with a central core. 1

Types and Characteristics of Foot Corns

• Hard corns (heloma durum): Most common type, typically found on the tops and sides of toes or under the foot
• Soft corns (heloma molle): Occur between toes, particularly in the fourth interspace (65% of cases), and have a whitish, macerated appearance due to moisture 2
• Seed corns: Small, discrete lesions that typically appear on the sole of the foot

Corns differ from calluses in that:

• Corns have a central core or nucleus that can be painful when pressed
• Corns are typically smaller and more defined than calluses
• Corns are characteristically painful, while calluses may be painless 3

Causes and Risk Factors

Foot corns develop due to:

1. Mechanical stress: Repetitive pressure or friction on specific areas of the foot 1
2. Improper footwear: Shoes that are too tight, narrow, or high-heeled 4
3. Foot deformities: Such as hammertoes, bunions, or other abnormal foot mechanics that create pressure points 1
4. Bony prominences: Underlying bone structure that creates pressure points 2
5. High activity levels: Increased walking or standing that intensifies pressure on the feet 1

Clinical Assessment

When examining a suspected corn:

• Differentiate from plantar warts by gentle paring with a scalpel:
  • Corns will reveal normal tissue underneath
  • Warts will show soft, granular tissue with black dots (thrombosed capillaries) 3
• Assess location and characteristics (size, hardness, pain level)
• Evaluate footwear for proper fit and pressure points
• Check for underlying foot deformities that may be contributing factors 4

Management Approach

Conservative Treatment (First-Line)

1. Reduce pressure and friction:

   • Wear properly fitting shoes with adequate width and rounded toe box 4
   • Use shoes with flexible flat soles and heel support 4
   • Consider cushioning insoles or orthotics to redistribute pressure 4

2. Gentle debridement:

   • Soak feet in warm water to soften the corn
   • Gently debride thickened tissue using a pumice stone or emery board 4
   • Avoid excessive debridement which can increase tenderness 4

3. Padding and protection:

   • Apply corn pads to redistribute pressure away from the corn
   • Use toe spacers for soft corns between toes 4

Preventive Measures

• Regular moisturizing after foot baths to prevent skin dryness 4
• Proper footwear selection with adequate room in the toe box 4
• Self-monitoring for signs of skin breakdown 4
• Avoid over-the-counter chemical corn removers, which can damage healthy tissue 4

When to Consider Referral

• Persistent or recurrent corns despite conservative management
• Corns in patients with diabetes, peripheral vascular disease, or neuropathy
• Signs of infection (redness, warmth, drainage)
• Underlying foot deformity requiring correction 5

Special Considerations

Diabetic Patients

Patients with diabetes require special attention due to:

• Increased risk of infection and poor wound healing
• Possible neuropathy masking pain from corns
• Higher risk of ulceration at pressure points 5

For these patients:

• More frequent foot inspections (every 1-3 months for high-risk patients) 5
• Therapeutic footwear to prevent ulceration 5
• Prompt professional treatment rather than self-care 5

Conclusion

Most foot corns can be effectively managed with conservative approaches focused on reducing pressure and friction through proper footwear and gentle debridement of hyperkeratotic tissue. Surgery is rarely indicated and should only be considered when conservative measures fail, specifically aimed at correcting abnormal mechanical stresses causing the corn 1, 6.