Cold-related injuries have been described since antiquity in
the medical and historical literature.1 Their occurrence depends on the degree of cold exposure, as
well as environmental and individual factors. Cold-related injuries
develop either directly, by tissue cooling, or secondarily, through
cold-associated injuries causing straings, sprains, or other trauma
and predisposing a person to frostbite and other local cold injuries.
Injuries sustained in a cold environment may predispose a person
to nonfreezing cold injuries, frostbite, or hypothermia (Figure 202-0.1). Hypothermia is discussed in Chapter 203, Hypothermia.
Cold exposure and cold injuries algorithm.
Frostbite is the prototype freezing injury and is seen only when ambient
temperatures are well below freezing. Nonfreezing cold injuries
occur as a result of exposure to wet conditions when temperatures
are above freezing. The most common nonfreezing cold injuries are
trench foot and chilblains. Although frostbite may result in permanent
tissue damage, nonfreezing cold injuries are characterized by usually
mild but uncomfortable inflammatory lesions of the skin. This chapter
describes the occurrence, risk factors, treatment, and prevention
of the nonfreezing cold injuries—trench foot and immersion
foot, chilblains or pernio, panniculitis, and cold urticaria—and
the freezing injury—frostbite.
Trench foot was given its current name because of the frequency
with which it was diagnosed among World War I troops confined in
trenches filled with standing cold water. Significant numbers of
cases were also seen in the Falkland, Korean, and Vietnam wars.
Immersion foot is a more severe variant of trench foot seen in downed
pilots and shipwrecked sailors exposed for extended periods in life
rafts in the North Atlantic Ocean. Trench foot and immersion foot, are rare in civilians, although they remain
a significant problem in military operations. Nowadays, trench foot
is occasionally seen in workers exposed to primitive wet circumstances
(jungle rot), in victims of shipwreck who have spent several hours
in lifeboats or on rafts, in those in military training, and in
persons who have been hiking or camping or on an expedition.
The pathophysiology of trench foot is multifactorial but involves direct
injury to soft tissue sustained from prolonged cooling, and it is
accelerated by wet conditions. The peripheral nerves seem to be
the most sensitive to this form of injury. Trench foot develops
slowly over hours to days and is reversible initially but becomes
irreversible if allowed to progress. Cold and wet conditions above
freezing lower the skin temperature, which leads to vasoconstriction,
red cell and thrombocyte plugging, tissue edema, and nerve and small-vessel
injury. Individual sensitivity, including immunologic factors, likely
contributes to the development of nonfreezing cold injury.
Early symptoms progress from tingling to numbness of the affected
tissues. On initial examination, the foot is pale, mottled, anesthetic, pulseless,
and immobile, which initially does not change after ...