| Patients
with cold urticaria develop whealing on exposure to cold.
Wheals typically appears on exposed areas on a cold day. Handling
of cold objects also causes immediate local reaction. There
may be swelling of the mouth and oesophagus after drinking
cold water. If whealing is extensive, cold urticaria may be
associated with systemic symptoms like faintness, wheezing
and palpitations.
Diagnosis is established by placing an ice
cube (wrapped in plastic bag) on the skin for 30 seconds to
10 minutes. Wheals form on rewarming. In some cases, water
at 7o C is more effective in bringing out the wheal.
It is important to warn patients against swimming
in cold water or immersing in cold water as syncope may occur.
Antihistamine treatment is partially effective in suppressing
symptoms. Cyproheptadine is generally considered to be the
drug of choice. Salbutamol and aminophylline can relieve the
pruritus of cold urticaria.
Unlike antihistamines these drug act by suppressing
histamine release from skin mast cells. Doxepin and ketotifen
may also be useful.
Desensitization to cold has a place in the
management of this condition. This should be carried out in
the hospital under antihistamine cover. The procedure begins
with putting one limb in water at 15 ?C for 5 min, hourly
at first and then at longer intervals up to 24 hours.
Other limbs and the face can then be treated.
The exposure needs to be repeated indefinitely at 24 hours
intervals to maintain the effect.
It should be remembered that occasionally
cold urticaria is secondary to the presence of cryoglobulin,
cold hemolysin and cryofibrinogen in the circulation. These
condition should be ruled out accordingly.
What
is Urticaria ?|Classification
of Urticaria|Chronic
Idiopathic Urticaria|Cholinergic
Urticaria|
Cold
Urticaria| Urticaria
causes|Traditional
Chinese Medicine and Urticaria|Pressure
Urticaria|
Solar
urticaria
|
