A corn (clavus, heloma) is a common foot problem in athletes or the elderly.


General features:

(1) hyperkeratotic plaque, often ring-shaped

(2) usually painful

(3) has a central translucent keratin core


Risk factors for occurrence:

(1) ill-fitting shoes that compress toes or cause areas of increased pressure

(2) toe disorder (clawtoe, hammertoe, overlapping toes)

(3) pressure or friction over a metatarsal condyle

(4) increased body weight or heavy loads

(5) on the feet for long periods of time (waitress, etc.)



(1) hard (heloma dura): occur over the dorsal interphallangeal joints, metatarsal heads, great toe

(2) soft (heloma molle): occur in the interdigital space, especially the fourth

(3) vascular

(4) neurovascular


Onchoclavus is a hard corn that occurs beneath a toe nail.


Differential diagnosis:

(1) plantar wart (has a core of thrombosed capillaries)

(2) callus (a callus can have a central corn)

(3) dermatophyte infection with hyperkeratosis



(1) proper fitting shoes

(2) cushioning pads, especially over the metatarsal condyles

(3) plastic devices or cushions to keep the toes apart



(1) paring away (debridement) of the thickened keratin layer

(2) liquid nitrogen

(3) laser reshaping

(4) surgical removal of condyles from metatarsal or phalangeal bone

(5) surgical correction of toe abnormalities


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