category and are the most easily correctable. Common
examples include constrictive clothing and jewelry,
prolonged contact with heat conductive materials, and
Of the 3 types of NFCI, frostnip is the least severe. It
typically affects the distal extremities after prolonged
exposure to cold but nonfreezing temperatures. Ice crystal
formation and profound vasoconstriction are common in
the superficial tissues, and patients frequently complain of
a dull throbbing pain during rewarming. Essentially a
precursor to frostbite, overt tissue destruction is lacking.
nonfreezing but cold and wet environment. Although
chilblains can affect any area of the body, the face, dorsal
surfaces of the hands and feet, and pretibial tissues are the
most commonly involved. Permanent tissue damage
secondary to vascular inflammation and tissue bed hypoxia
may develop. Women, children, and patients with
underlying vasculitides are most commonly affected.
Immersion foot develops after the prolonged exposure
to persistently wet conditions, both warm and cold,
although the latter typically results in more severe tissue
injury. The long-term exposure to moisture induces tissue
edema and inflammation, whereas the prolonged cold
exposure leads to direct tissue injury. The consequently
encountered vasospasm, intravascular thrombosis, and
neuronal destruction can lead to full-thickness tissue loss.
Immersion foot is most commonly seen in the homeless
Frostbite involves the freezing of tissues and can
result in significant tissue loss and long-term disability.
Ice crystal formation within the extracellular space can
induce intracellular dehydration, enzymatic dysfunc
tion, and cellular death. Microvascular occlusion sec
ondary to profound vasospasm and intraluminal
thrombosis further the severity of tissue loss. Circulating
tissue inflammatory markers frequently exacerbate the
intensity of tissue injury and complicate the reperfusion
Taking an adequate history should never delay the removal
of a patient from a cold environment. Inquire about
previous medical or psychiatric illnesses, drug and alcohol
use, and housing status. Any history of trauma should be
documented. Try to identify the overall duration of cold
exposure and elicit any previous history of frostbite or a
thawing and refreezing pattern of tissue injury. The review
of symptoms should attempt to discover the presence of
altered sensitivity, numbness, or burning pain.
Frostnip generally presents with numbness, pain,
pallor, and paresthesias of the ears, nose, fmgers, and toes.
Patients with chilblains typically present with complaints
of erythema, edema, and an intense pruritus or burning
sensation. Immersion foot is usually associated with
significant pain and swelling and occasionally numbness
and/or the inability to ambulate. Frostbitten patients
generally complain of the inability to feel the affected
Remove all clothing and thoroughly examine the entire
body, focusing primarily on the face, hands, lower legs and
feet, and buttocks and genitalia. Patients with frostnip may
present with paleness of the affected areas, but a normal
exam does not rule out injury. Chilblains frequently present
with erythema and edema and occasionally with vesicles,
bullae, and even ulcerations. The characteristic lesions are
and erythematous. Tissue sloughing is common, and there
may be an associated malodor. Frostbite typically presents
with mottled or violaceous tissue that may have a waxy
Figure 62-1. Deep frostbite of the toes.
.A. Figure 62-2. Superficial frostbite. Note the tissue
appearance. Although frostbite can be classified similar to
burns into superficial and deep tissue injuries, this distinction
often cannot be made until the tissue is properly rewarmed.
necrosis can complicate cases of deep tissue freezing despite
minimal initial physical exam findings.
Diagnostic studies of any kind are of limited utility in the
initial evaluation of patients with cold inducted tissue
injuries. That said, pursue radiographic and laboratory
studies as dictated for the evaluation of concurrent medical
illness or traumatic injury. Radionuclide bone scanning
and magnetic resonance imaging may a prognostic role in
temperatures, but evaluate and treat for any life-threatening
conditions before dealing with these injuries. Check the c ore
body temperature of all cold exposed patients to rule out
hypothermia. Investigate for and address any concurrent
unclear between the two, always err on the side of frostbite
and treat accordingly. Consider compartment syndrome in
frostbitten regions if the swelling does not resolve and pulses
do not return after adequate rewarming.
Keep in mind that other injuries or illnesses can both
mimic and contribute to cold-induced tissue injury.
For example, the erythema of rewarmed frostnip and
immersion foot can resemble cellulitis or deeper tissue
infections. Peripheral vascular disease and vasculitides not
only appear similar to both frostbite and chilblains but also
frostbite can be confused with both stasis dermatitis and
autoimmune bullous forming conditions (Figure 62-3 ).
Figure 62-3. Cold-ind uced tissue injuries
All clothing should be removed and replaced with warm
blankets. Wet clothing is especially problematic as it will
continue to cool the patient during treatment. Dehydration
is a common complicating condition and requires
aggressive volume resuscitation with intravenous (IV)
crystalloids to lessen blood hyperviscosity. All body parts
that have suffered cold-induced tissue injury will need
some type of rewarming, with the pattern of injury
sustained determining the appropriate modality.
Frostnip usually resolves spontaneously with dry
rewarming measures at room temperatures and requires
no further intervention. Rewarm chilblains affected skin at
room temperature and then wash, dry, and dress in a soft
sterile bandage. Initiate pain control as needed and elevate
the affected extremity to prevent excessive edema
formation, as this will predispose to subsequent infection.
Patients with recurrent episodes may benefit from
treatment with oral nifedipine (30-60 mg/day), and topical
and systemic corticosteroids have both shown promise in
Immersion foot requires slightly more detailed care.
Rewarm affected tissues at room temperature and allow
them to air dry. Restrict patients to bed rest and elevate the
affected extremities during the rewarming period. Certain
patients may achieve adequate pain relief with oral
nonsteroidal anti-inflammatory drugs, whereas others may
require parental opioid analgesia. The early use of t ricyclic
antidepressants may help limit the future development of
chronic neuropathic pain. Extreme cases of immersion
foot may be indistinguishable from frostbite and should be
treated as the latter until proven otherwise. Finally, all
patients with NFCI require clear instructions to limit their
potential for recurrent exposure and injury.
Frostbite requires more aggressive treatment to limit
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