Cold urticaria: its importance in the operating room.

Cold urticaria is one of the least common types of urticaria, affecting approximately 1% to 3% of all patients with urticaria [1]. Patients present generalized or local wheal lesions in areas that come into contact with cold stimuli such as cold air, water, or objects. The symptoms may or may not be accompanied by angioedema. Cold urticaria can be primary or associated with other pathologies such as cryoglobulinemia, infections, leukocytoclastic vasculitis, or neoplasia. The greatest risk with this kind of urticaria is the development of a systemic reaction resulting in hemodynamic collapse during generalized cold exposure (eg, swimming in the sea or a swimming pool). We report the case of an 82-year-old man with a background of allergy to penicillin. The patient had been scheduled for aortic endoprosthesis implantation to treat an aortic aneurysm. On the day of surgery, he was premedicated with 2 mg of midazolam in a saline solution with no additives. Some minutes later, he was transferred to the operating room and the saline solution was infused again. He immediately presented erythema and itching in the perfusion area on the left arm, following the outline of the veins. The peripheral catheter was consequently removed and placed in the right arm, but the same reaction appeared after infusion of the saline solution. The nurse had used sterile latex gloves to place the catheter. Methylprednisolone 125 mg and a vial of dexchlorpheniramine were administered, and the symptoms yielded. Nevertheless, when the saline solution was infused again, the symptoms returned, and surgery was stopped. In the allergy study, skin tests to latex, which was considered a possible triggering factor, were negative, as were prick and intradermal tests to midazolam. An ice cube test was performed by placing an ice cube covered with parafi lm on the patient’s forearm for 10 minutes, with readings taken at 5 and 20 minutes. A positive wheal of 35x30 mm exceeding the limits of the ice cube was observed after 20 minutes. At this time, the patient reported having experienced on other occasions symptoms of acute urticaria after contact with cold water, with no other symptoms Surgery was rescheduled for the next day. The temperature in the operating room was increased and the sera were heated. Corticosteroid and antihistamine premedication was administered, and the operation was performed without complications. The administration of midazolam was avoided. Allergic reactions to the drugs used in anesthesia are a frequent cause of morbidity in the operating room. We report the case of a patient who experienced a skin reaction before the administration of anesthetics. Once latex allergy had been ruled out as a possible trigger, the patient was questioned again about his history, and he reported reactions compatible with cold urticaria. This is a rare form of allergy in the operating room, where the temperature is usually 19oC to 21oC [2], but patients can sometimes present hypothermia symptoms before the beginning of surgery. Data about the temperature of solutions administered to patients are not available, but solutions administered during surgery are usually cold, since in most cases they are at the same temperature as the room and are not heated before being infused into the patient. Consequently, they can cause reactions such as that experienced by our patient. Avoidance of exposure to cold is the most important prevention measure and in patients in whom symptoms are frequent, the administration of antihistamines is common [3]. For patients with an insuffi cient response to antihistamines, antileukotrienes [4] or even an anti-immunoglobulin E monoclonal antibody (omalizumab) [5] should be considered.