This is not the most recent version of the article. View current version (11 MAY 2011)
Intervention Review
Heated, humidified air for the common cold
Editorial Group: Cochrane Acute Respiratory Infections Group
Published Online: 8 JUL 2009
Assessed as up-to-date: 6 MAY 2006
DOI: 10.1002/14651858.CD001728.pub3
Copyright © 2009 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
Database Title
Additional Information
How to Cite
Singh M. Heated, humidified air for the common cold. Cochrane Database of Systematic Reviews 2006, Issue 3. Art. No.: CD001728. DOI: 10.1002/14651858.CD001728.pub3.
Publication History
- Publication Status: Edited (no change to conclusions)
- Published Online: 8 JUL 2009
This is not the most recent version of the article.View current version (11 May 2011)
Abstract
Background
Heated, humidified air has long been used by common cold sufferers. The theoretical basis is that steam may help congested mucus drain better and heat may destroy cold virus as it does in vitro.
Objectives
To assess the effects of inhaling heated water vapour (steam), in the treatment of the common cold by comparing symptoms, viral shedding and nasal resistance.
Search strategy
In this updated review we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2005, issue 4); MEDLINE (2003 to December Week 2 2005); EMBASE (July 2003 to September 2005); and Current Contents (current five years).
Selection criteria
Randomized controlled trials (RCTs) using heated water vapor in patients with the common cold or volunteers with experimentally induced common cold.
Data collection and analysis
All the articles retrieved were initially subjected to a review for inclusion or exclusion criteria. Review articles, editorials and abstracts with inadequate outcome descriptions were excluded. Studies selected for inclusion were subjected to a methodological assessment.
Main results
Six trials were included. Three found benefits of steam for symptom relief with the common cold (odds ratio (OR) 95% confidence interval (CI) 0.31; 0.16 to 0.60; relative risk (RR) 0.56; 95% CI 0.4 to 0.79). Results on symptom indices were equivocal. No studies demonstrated an exacerbation of clinical symptom scores. One USA study demonstrated worsened nasal resistance, while an earlier Israeli one showed improvement. One study examined viral shedding and antibody titres in nasal washings: there was no change of either between treatment and placebo groups. Minor side effects (including discomfort or irritation of the nose) were reported in some studies.
Authors' conclusions
Steam inhalation are not recommended in the routine treatment of common cold symptoms until more double-blind RCT trials are conducted.
Plain language summary
There is not enough evidence to show if steam inhalation improves or exacerbates nasal congestion when a person has a cold
The congestion from the common cold, arising from swelling of the membranes and thickened mucus inside the nose, has been treated for decades with inhaled steam in the hope this makes the mucus drain away easier. Also there is laboratory evidence that cold virus may be sensitive to heat. However this review found that in some studies, inhaling steam helped symptoms, others did not, so there was not enough evidence to be sure. There were some adverse effects (discomfort or irritation on the nose or lips). No studies included children.