Inherent in walking or
running is the battle between a fixed surface (the floor) and the foot
delivering force with each step. Each step results in friction that can
irritate the ball of the foot and the toes. In a response to friction, skin will
often thicken to form a protective outer layer. We call this thickening a
corn or callus.
Corns and calluses come in all shapes,
sizes and varieties. Corns can be found on the tops of toes, between toes, at
the tips of toes
or even adjacent to the nail. A corn is simply the formation of
a callus on a toe. The terms corn and callus can be used interchangeably, but
for sake of conversation, a callus is a build up of skin on the bottom of the
foot or heel, while a corn is a build up of callus on the toes. Initially, the
formation of callus can be a helpful process. As the skin senses a mechanical
irritation it responds by thickening, forming a callus. What do we mean by
mechanical irritation? Well that could be a shoe that is too tight, it could be
friction against the ground or it could even be the mechanical friction that
occurs between two toes. In each case, corns form by the recurrent rub of
mechanical friction.
The most common corn is
due to contraction of the toe (hammer toe) placing pressure on the top of the toe from the toe box of the shoe. This type
of corn, is referred to as a helloma dura (HD), or hard corn, and is often seen
in cases of hammer toes where the toe is contracted and pushing against the roof
of the shoe. Soft corns, on the other hand, are found between the toes. Soft
corns, also known as HM's (helloma molle) or kissing corns, are commonly
misdiagnosed as a chronic athlete's foot infection. With soft corns, we’ll see
a breakdown of the skin between the toes. This breakdown is usually between the
4th and 5th toes.
Treatment of corns
The most important aspect
of treating a corn is to be sure that the shoe is properly fit. Consider the
formation of a hard
corn to be no more complicated than the analogy of a square
peg and a round hole. The foot is the square peg that just doesn't fit into the
round hole (the shoe). Our choices are to make the round hole (shoe) bigger or
softer by wearing a wider or softer shoe. Or we make the foot (square peg) more
narrow by surgically correcting the foot. Alternatively a corn pad can also be
used to cushion the corn. Common sense would tell us to first try to modify the
shoe or use a corn pad.
The distal end of the shoe that covers the toes is called the toe box. The
width and depth of the toe box are very important when trying to obtain a good
fit. An improperly fit toe box can contribute to developing corns. Try this
simple test. Stand barefoot on the floor. Place your shoe on the floor right
next to your foot. Now compare the shape of your forefoot and the shape of the
toe box. If the two are incompatible, you're looking for trouble and asking for
a corn.
Corn pads
and
callus pads come in all
kinds of shapes and sizes. Choosing the correct pad depends upon three things;
(1) the location of the corn or callus (2) the type of shoe in which you intend to wear
the pad and (3) the activity you plan to participate in while wearing the pad.
Soft corns respond to the use of a pad that separates the toes.
Soft corn pads can
be made from silicone gel, soft foam or lambs wool. Many folks find relief with
a simple cotton ball that’ll separate the toes. Foam and gel toes sleeves are
another popular solution for hard corns. Hard corns can also be treated with
gel cushions and adhesive backed felt ‘cut out’ pads.
Periodic paring
(debridement) of a hard corn can help to reduce the thickness of the callus.
This can be accomplished with a
safety razor,
callus file or
pumice stone.
Topical callus creams can also be used to soften callus prior to
debridement. Care should be exercised with medicated callus creams in
patients with poor circulation or loss of sensation (peripheral
neuropathy).
Permanent correction of
corns can be accomplished by a number of different surgical procedures. The
procedures vary dramatically based upon the type and location of the corn. Some
corns are quite easy to correct, others a bit more difficult. Your podiatrist
can help you determine whether you may be a candidate for surgical correction of
your corn.
Well fitted shoes, a dose
of prevention and a knowledge of treating corns can make a world of difference
in your comfort.
