—To test the efficacy of steam inhalation in treating common cold symptoms.
—An in vitro study determined the temperature that inactivated rhinovirus: a temperature of 43°C lasting at least 1 hour was needed. We then conducted a double-blind, placebo-controlled, randomized in vivo study.
—The virology laboratory and the outpatient department of the Cleveland (Ohio) Clinic Foundation.
—Sixty-eight Cleveland Clinic employee volunteers with symptoms of the common cold at the time of enrollment.
—A single 60-minute treatment was given to the volunteers. The steam treatment group (n=32) received 40 L/min of heated saturated air that raised the intranasal temperature to 43°C. The placebo group (n=36) received 2 L/min of ambient air at 20°C to 24°C.
Main Outcome Measures.
—Subjective symptom scores for nasal congestion, nasal drainage, and sneezing and objective measures of nasal resistance were studied during a 7-day follow-up observation period.
—There were no significant differences in daily symptom scores between the groups (P=.59 to.83). The only statistically significant differences between the groups were lower nasal resistances at baseline in the steam group (P=.04) and percent improvement in nasal resistance favoring the placebo group on day 7 (P=.01). However, these differences were of questionable clinical significance.
—We conclude that steam inhalation treatment had no beneficial effect on the cold symptoms of our volunteers.(JAMA. 1994;271:1109-1111)