Exposure to damp, cold conditions can result in tissue damage
of the foot. This condition is called trench foot, immersion foot,
chillblains or pernio. The mechanism of soft tissue damage in these conditions is not fully
understood. Cellular damage occurs to the skin, subcutaneous tissue, blood vessels and
nerves. The longer the exposure to cold, the greater the chance of
injury. Injury may be temporary or may result in permanent damage
particularly to the nerves of the feet. Chillblains is used to describe
permanent symptoms following one or more incidents of trench foot.
Trench foot is the term that is used to describe injuries of the foot due to
water and cold exposure at sustained temperatures ranging
from 32-65 degrees Fahrenheit. Trench foot differs from frostbite in that
frostbite is the actual freezing of cells at or below 32 degrees Fahrenheit.
Another difference between trench foot and frostbite is that frostbite can easily occur
in the absence of moisture.
The symptoms of trench foot include burning and tingling of the feet. Loss
of sensation is common. The effected portions of the foot and toes can
appear cyanotic (gray) and blotchy. When warming the feet after cold
exposure, burning can become severe. Maceration and fissures of the skin
are common. Blisters, erythema (redness) and skin that peels are also
common with repeated exposure to the cold.
The term immersion foot is used to describe both cold and warm
weather injuries. Warm water immersion foot and tropical immersion foot
describe two clinical types of tissue damage that occur with prolonged exposure
to moisture. Warm water immersion foot can occur in folks with excessive
perspiration who work in enclosed rubber boots. Warm water immersion foot
and tropical immersion foot symptoms include painful thickening and maceration
of the skin of the bottom of the foot. Warm water immersion foot and tropical
immersion foot are found most commonly in adolescents and young
adults.
Quite often we'll see that a person's occupation contributes to
warm water immersion foot. Workers who wear boots, particularly rubber boots
and insulated boots, are most susceptible to trench foot and warm water
immersion foot. The jungles of Vietnam and combat boots were a 'shoe in' for
tropical immersion foot.
Treatment of trench foot and immersion foot
Prevention becomes the key in treating trench
foot and immersion foot. Limiting exposure to cold is essential in
preventing and treating trench foot. Maintaining a dry environment within
the shoe is a must. Controlling hyperhydrosis (excessive
perspiration) can help. Remember, when treating hyperhydrosis this
condition can not be cured, but rather needs to be managed over a patient's lifetime. Some
of the methods used to treat hyperhydrosis are really quite simple. Create
and environment in the shoe that is cool, dry and accessible to UV light.
Try these four simple tricks;
1. Rotate your shoes every other day
to allow them to dry thoroughly.
2. Avoid synthetic materials like rubber or vinyl. Wear leather or cloth that
can absorb moisture.
3. Frequent changes of socks to wick away moisture.
4. Use talc or baby powder daily to wick away moisture.
Drying agents are useful to help control perspiration. Aluminum chloride is
the most commonly used topical drying agent. Formalin is used in other prescription strength
medications. Antihistamine and anticholinergic medications are used in
severe cases. These medications include Benadryl, Banthine or
Pro-Banthine.
Severe cases of hyperhydrosis can
also be treated with injections or surgery. Recently, injections of Botox,
or attenuated botulism, has been used very successfully by podiatrists and dermatologists.
Botox is used to paralyze the smooth muscle that regulates the sweat
glands of the bottom of the foot. Endoscopic excision of the dorsal root ganglion is a method used by
neurosurgeons to create surgical anhydrosis (absence of perspiration) by surgically removing that
component of the nervous system responsible for autonomic functions such as
perspiration.
