Asthma induced by ice water ingestion in ethnic Chinese asthmatic children: a challenge

Abstract

The purpose of this study was to investigate the relationship between ice water ingestion and the induction of asthmatic symptoms and signs in ethnic Chinese asthmatic children. Sixty asthmatic children with a positive history of exacerbation of symptoms after drinking ice water were divided randomly into two groups: 34 children were instructed to drink 250 ml of 0-4 degrees C ice water within one minute, and 26 to drink 250 ml of 25 degrees C warm water. All of the asthmatic children were stable when studied. Twenty-three healthy children as controls were asked to drink 250 ml of 0-4 degrees C ice water. The three groups had forced expiratory volume in one second (FEV1) performed at baseline and at 5, 15, 30, 60, and 90 minutes after challenge. After the spirometric test at 90 minutes the patients of the two asthmatic groups received three puffs (0.6 mg) of hexoprenaline MDI and a further spirometric test was performed 5 min after the inhalation. Cough and wheeze were monitored throughout the course of the test. The mean FEV1 after challenge decreased significantly only in the ice-water asthmatic group (p = 0.004). Compared with the baseline data, the mean FEV1 at various periods after challenge was only significantly decreased at 60 min (p = 0.035). After hexoprenaline inhalation the FEV1 significantly increased in the two asthmatic groups (p < 0.001). A significant difference in FEV1 change was noted among the three groups (p = 0.015). Nine cases (26%) from the ice water asthmatic group, three (12%) from the warm-water asthmatic group, and none of the ice-water normal control group showed a decrease of FEV1 greater than 15% (p = 0.018). The greatest difference occurred between the two ice water groups. All six cases who developed symptoms after challenge, accompanied by a simultaneous decrease of FEV1 greater than 15%, belonged to the ice-water asthmatic group. Forty-seven percent of the ice-water asthmatic group and 4% each of the two other groups had cough and/or wheeze after challenge (p = 0.0002). Ice water ingestion may induce or exacerbate asthma in ethnic Chinese asthmatic children.