skin corn (clavus)

Introduction

Skin callus over a bony prominence.

Classification

• hard corns:
  • generally seen of dorsal aspect of lesser toes & lateral aspect of 5th toe
• soft corns:
  • found in web space between toes (most commonly 4th web space)
  • pressure point lies between 2 adjacent phalanges
  • maceration of the corn in a web space makes it soft
• seed corns: (plantar clavi)
  • found on plantar surface of the foot

Etiology

• improper footwear
• structural deformities
  • hammer toes with exostosis
  • other bony prominences

Clinical manifestations

• corns have more distinct edges & are more rounded than calluses
• plantar corns are conical-shaped & have a central area extending toward sensitive subcutaneous tissue
• frequently occur on the sides or tops of toes
• corns produce pain when foot is placed in a tightly-fitting shoe
• plantar corns produce pain on weight bearing

Laboratory

none

Differential diagnosis

• plantar warts (more vascular than corns)
• foreign body with secondary keratosis
• rule out infection & ulcerations in diabetic patients

Management

• debridement of excess build-up of epidermis
• enucleation of apex or central area of corn
• corn pads to reduce pressure over bony prominences
• proper footwear
• liquid nitrogen
• salicylic acid (non-surgical candidates)
• referral to podiatrist when conservative measures fail

More general terms

• skin callus