a frigore - Alergología e Inmunología Clínica

Table V. Complementary explorations and analyses
recommended in the study of a cold urticaria patient
Complete blood count, ESR Antinuclear antibodies
Blood biochemistry with liver C3, C4, CH50
function tests Serologies (Epstein-Barr virus, syphilis,
T4, TSH hepatitis B and C, echinococcosis,
Protein electrophoresis Chlamydia, Mycoplasma
Immunoglobulin quantitation Parasites and ova in faeces
Cryoglobulins Plain chest film
The most commonly used cold challenge test is the
ice-cube one, in which an ice cube is placed for four minutes
upon the volar aspect of the patient’s forearm and
the stimulated area is inspected ten minutes later. Patients
with cold urticaria usually manifest pruritus in the stimulated
area two minutes after removal of the ice cube and develop
a wheal reproducing the size and shape of the ice
cube after ten minutes 2 . A longer contact time (20 minutes)
has been suggested to increase the sensitivity of the
test. Furthermore, a correlation appears to exist between
the time required for a positive result to appear and the intensity
of the urticaria, so that earlier positivities imply a
greater risk of systemic manifestations and thus of hypotension
or anaphylactic shock 6 .
If the ice-cube test is negative, the next test to perform
is the immersion of the arm in cold (5-10ºC) water
for five to ten minutes. If these two tests are negative, but
the clinical suspicion persists, total body exposure to cold
may be carried out by placing the lightly-clothed patient
for a certain period (5 to 30 minutes) in a room with an
environmental temperature of 4ºC. Strict and close medical
control is imperative in this case because of the risk of
triggering systemic symptoms.
In order to rule out the presence of underlying disease
in these patients, the complementary assessments summarised
in Table V are recommended 5,6,11 .
MANAGEMENT
The most important aspect in the therapeutic management
of cold urticaria is that of the preventive measures.
Therefore, the patient should be warned of the risk implicit
in a number of situations of activities that may represent a
threat to life, such as the ingestion of cold meals or beverages
or practising aquatic or sports activities at low environmental
temperatures. An ice-cube test with a positive res-
Urticaria a frigore
ponse after less than 3 minutes is considered to be a risk factor
contraindicating the practise of water sports 5 . If the patient
is to undergo surgery a number of precautionary measures
should be observed, such as the administration of
intravenous infusion at a temperature of 37ºC and raising the
temperature in the operating theatre. Patients with a high degree
of cold sensitivity should be given epinephrine and corticosteroids
for self-administration should the need arise 15 .
Regarding drug therapy, antihistamines may be effective
in reducing or suppressing the symptoms. Even
though ciproheptadine was long considered to be the drug
of first choice, it has been relegated by the newer non-sedative
antihistamines with a lesser rate of side effects. The
association of H 1 and H 2 antihistamines does not appear to
have evidenced greater efficacy than the use of H 1 antihistamines
alone 2,15 . Doxepine, a tricyclic antidepressant with
marked H 1 antihistamine effects, has been used with success
at a dose of 50-75 mg/day in cases with insufficient
or scarce response to antihistamine therapy 16 . Stanazolol (a
synthetic testosterone-derived anabolic steroid with minimal
androgenic effects) has been demonstrated to be effective
in the management of familial cold urticaria 17 . In
cooperative patients with a high level of motivation, some
authors propose induction of cold tolerance or cold desensitisation,
in which the patient undergoes progressive contact
with cold water with gradual increase of the exposure
time and of the exposed body surface until he/she tolerates
total body immersion. This procedure should be carried
out with the patient admitted into hospital because of the
risk of triggering an anaphylactic reaction during the tolerance
induction procedure 15 .
REFERENCES
1. Kontou-Fili K, Borici-Mazi R, Kapp A, Matjevic LJ, Mitchel FB.
Physical urticaria: classification and diagnosis guidelines. Allergy
1997; 52: 504-513.
2. Kaplan AP. Urticaria and angioedema. En: Middelton E, ed.
Allergy. Principles and practice. Barcelona: Salvat, 1998; 1104-
1119.
3. Mathelier-Fusade P, Bakhos D, Chabane MH, Leynadier F. Clinical
predictive factors of severity in cold urticaria. Arch Dermatology
1998; 134: 106-107.
4. Hoffman HM, Wright FA, Broide DH, Wanderer AA, Kolodner RD.
Identification of a locus on chromosome 1q44 for familiar cold urticaria.
Am J Hum Genet 2000; 66: 1693-1698.
5. Wanderer AA. Cold urticaria syndromes: historical background,
diagnostic classification, clinical and laboratory characteristics, pathogenesis
and management. J Allergy Clin Immunol 1990; 85: 965-
981.
6. Hermes B, Prochazka, AK, Norbert H, Jurgovsky K, Sticherling
M, Henz BM. Upregulation of TNF-α and IL-3 expression in lesional
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