[Urticaria caused by cold. 104 cases].
INTRODUCTION: Superficial and deep cold urticaria is a heterogeneous group of manifestations induced by exposure to cold (0 to 4 degrees C). Frequency is generally estimated at 2 to 3 p. 100. We studied retrospectively 104 patients meeting clinical, biological and therapeutic criteria of cold urticaria. PATIENTS AND METHODS: From 1981 to 1995, 1802 patients with urticaria were included in a standardized allergy survey. Among these patients, 104 met the criteria for the diagnosis of cold urticaria: positive test with 3 ice cubes placed on the skin for 5, 10 and 15 minutes or positive immersion test (immersion in 4 degrees C water for 15 minutes). Two groups of patients were excluded, those with systemic cold urticaria and those with minimal thermo-differential urticaria. RESULTS: Cold urticaria was found in 5.7 p. 100 of our urticaria patients, predominantly in young women. The triggering effect of cold was found at history taking in 71 p. 100 of the cases. The urticaria was usually superficial, more rarely associated with deep and/or mucosal urticaria. General signs were uncommon. The three ice cube test demonstrated significative biological and immunological abnormalities. In 5 cases, discrete cryoprecipitate was found (4 cryoglobulins, 1 cryofibrinogen). Although the search for an infectious agent was not conducted in absolutely all cases, there was no apparently remarkable association with infection the exception of VIH infection. Anti-H1 agents were given in 88.3 p. 100 of the cases leading to short-term improvement. Follow-up is insufficient to evaluate long-term outcome. DISCUSSION: This retrospective survey of 104 cases of cold urticaria was compared with data in the literature, particularly with the small number of studies including a large number of patients. We conclude that the diagnosis of cold urticaria can be based on history taking alone and the three ice cube tests (prognosis value, indication of reaction threshold). An exhaustive search for the cause is not indicated. A search for cryopathy should however always be done and followed by a complete work-up in case of positivity. Clinical signs other than cold urticaria suggesting a pathological response to cold require complete investigations.