Corns and calluses

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Corns and calluses are thickened areas of skin due to repeated pressure, friction, or irritation. Corns are well-defined horny papules or nodules that are often painful when pressed. Calluses are poorly defined areas of thickened skin that may be painful if cracks develop. Treatment is typically conservative, consisting of soaks, gentle exfoliation, moisturizing creams, topical keratolytic agents, and padding. Large and/or painful lesions may require scalpel debridement or surgical removal. The underlying mechanical cause (e.g., poorly fitted shoes, underlying foot and toe deformities) must also be addressed to prevent recurrence.

Hypertrophy of the stratum corneum secondary to repeated pressure, friction, or irritation caused by: ^[2][3]

• Poorly fitting shoes
• Manual occupations or hobbies (e.g., in weightlifters and musicians) ^[4]
• Foot deformities and toe deformities (e.g., hammer toe, hallux valgus)

Corns ^[5][6]

• General findings
  • Well-defined, circumscribed horny papule or nodule
  • Lighter-colored cone-shaped keratin center
  • Often tender when directly pressed
  • Skin lines are present over the lesion.
• Hard corns
  • Have a deep, firm central core
  • Typically located on the tops or sides of toes or the ball of the foot
• Soft corns
  • Macerated appearance
  • Typically located between the toes

Calluses ^[2][5]

• Poorly defined areas of thickened skin
• Typically located on the hands, fingers, or feet (beneath the metatarsal heads) ^[4][7]
• Skin lines are present over the lesion.
• Painful if cracks or fissures develop ^[7][8]

• Primarily a clinical diagnosis
• Diagnostic uncertainty: debridement or skin biopsy to exclude alternative diagnoses ^[2][9]
• Associated toe deformities: Consider imaging.

• Hard corns on the sole of the foot are often mistaken for plantar warts. ^[6]
• Soft corns are often mistaken for tinea pedis.

The differential diagnoses listed here are not exhaustive.

Initial management ^[2][3]

• All patients: Initiate conservative management.
  • Recommend warm water soaks followed by exfoliation (e.g., with a pumice stone).
  • Encourage the use of moisturizing lotions, creams, and/or emollients.
  • Consider an over-the-counter topical keratolytic agent, e.g, salicylic acid, urea. ^[10]
  • Apply padding (e.g., cotton, gel, foam) to the affected area while it heals.
• Large and/or painful lesions: Offer additional management.
  • Scalpel debridement (paring)
  • Hard corns: Refer for surgical interventions (e.g., corn enucleation, surgical excision). ^[5]

Patients with diabetes should not attempt to soften or treat corns and calluses themselves because of the risk of diabetic ulcers; refer to podiatry for management. ^[11]

Ongoing management and prevention of recurrence ^[2][3]

To remove the underlying mechanical cause and prevent reaccumulation of hyperkeratosis, initiate the following:

• All patients
  • Continue conservative interventions.
  • Refractory or recurrent symptoms: Refer for specialist evaluation.
• Hand involvement: Recommend using gloves or protective pads during activities that involve hand friction.
• Foot involvement
  • Recommend a shoe assessment to identify and correct poorly fitting shoes.
  • Keep toenails trimmed.