This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.
Nasal irrigation seems moderately effective for symptoms of sinusitis. People using nasal irrigation showed greater improvement in their sinus-related quality of life compared to people who didn’t use irrigation. They were also less likely to use over-the-counter medicines, and to have spent fewer days unwell with symptoms by six months.
Steam inhalation, meanwhile, seems to have minimal effect on quality of life compared with no inhalation. Neither treatment caused side effects or affected the rate of respiratory infections.
Sinusitis is common and can be difficult to treat, having considerable impact on daily life. Inhaling steam is a simple popular therapy, but past evidence has suggested that it’s not very effective. Previous studies have shown that nasal irrigation is effective, but these were small, hospital-based studies. This UK-based trial treated over 600 people in general practice. However, the trial did not directly compare nasal irrigation with steam inhalation. As such it is not possible to say with complete certainty that one is better than the other.
People need to perform nasal irrigation effectively to get maximum benefit and this may be difficult to maintain.
Why was this study needed?
Sinus problems are common affecting around 10% of UK adults. However, it can be difficult to find their exact cause leading to long-term symptoms that can negatively affect people’s quality of life.
People with sinus problems are often prescribed antibiotics, but past studies suggest they have only a modest effect and NICE recommend against their prescription. Previous systematic reviews also indicate that steam inhalation, despite its popularity, is not very effective. Whereas flushing out the nasal passage using a salt water solution showed promise as a potential treatment. This suggests some misalignment of what the evidence is saying and what people are doing in practice.
Past studies of nasal irrigation have been small and mainly from specialist settings, whereas most people with sinusitis are treated by their GP. Therefore, this randomised controlled trial aimed to compare GP advice to use steam inhalation or nasal irrigation with usual care.
What did this study do?
Adults (671) from 72 GP practices were randomly allocated to one of four advice strategies: usual care, advice on inhaling steam, advice on performing nasal saline irrigation, or advice on both steam inhalation and nasal irrigation.
Steam inhalation used a bowl of recently boiled water for five minutes. Nasal irrigation involved washing out the nose daily with 150ml of a home-prepared solution of one teaspoon of salt and half a teaspoon of baking soda in one pint of tap water.
Participants had experienced two episodes of acute sinusitis or one episode of chronic sinusitis in the past three years, and reported symptoms having moderate to severe impact on their quality of life. Outcomes were measured on the rhinosinusitis disability index (RSDI) – a self-assessment of the physical, functional and emotional impact on sinusitis. A ten point improvement (reduction in score) on this 100 point scale is thought to be clinically important.
The analysis of the four groups was by a 2x2 factorial design, where steam inhalation was compared with no steam inhalation, and nasal irrigation was compared with no nasal irrigation. As such this was not a direct comparison between the two interventions.
What did it find?
- At three months average RSDI scores had reduced slightly by 2.51 points with nasal irrigation compared no irrigation (95% confidence interval [CI] ‑4.65 to ‑0.37). Comparatively with steam inhalation scores had reduced by an average 0.73 points compared to no inhalation (95% CI ‑2.85 to 1.39). Suggesting a small effect of nasal irrigation and no effect of steam.
- At six months score reductions were still greater with nasal irrigation vs. no irrigation (‑2.41, 95% CI ‑4.66 to ‑0.16) than with steam inhalation vs. no inhalation (‑0.60, 95% CI ‑2.87 to 1.68).
- At six months, a greater proportion of people using nasal irrigation achieved a clinically meaningful 10-point decrease in their RSDI score: 44.1% with irrigation vs. 36.6% without irrigation. Comparatively the proportion was 41.5% with steam inhalation vs. 39.4% without inhalation.
- Both nasal irrigation and steam inhalation significantly reduced the likelihood of headaches compared with, respectively, no irrigation or no inhalation at three months, but not by six months. Nasal irrigation significantly reduced the use of over-the-counter treatments at six months but not three months. Neither treatment had a significant effect on the likelihood of adverse effects or respiratory infections compared with not receiving the treatment.
- By six months people receiving irrigation had spent fewer days unwell with sinusitis symptoms – an average of four days compared to seven days without irrigation.
What does current guidance say on this issue?
NICE recommends against prescribing antibiotics to otherwise healthy people who present with acute rhinosinusitis.
For chronic sinusitis, the Royal College of Surgeons (RCS) commissioning guidance advises treatment with nasal corticosteroids or nasal irrigation. Again, antibiotic treatment is not recommended. If symptoms do not improve after three months, the RCS recommends referral to a specialist.
What are the implications?
Nasal irrigation seems to have a beneficial effect on sinusitis symptoms compared with when it is not given, though the study authors note that it was less effective than observed in previous studies. Meanwhile steam inhalation seems to give little benefit.
Both nasal irrigation and steam inhalation are low cost treatments that people can administer in the comfort of their own home. With no difference in the rate of adverse effects, the apparent benefit of irrigation on the person’s quality of life suggests this may be the preferable option for GPs to recommend.
There might be a need to increase the amount of coaching to ensure that people are performing irrigation correctly to get maximum benefit.
Citation and Funding
Little P, Stuart B, Mullee M, et al; SNIFS Study Team. Effectiveness of steam inhalation and nasal irrigation for chronic or recurrent sinus symptoms in primary care: a pragmatic randomized controlled trial. CMAJ. 2016;188(13):940-9.
The study was funded by a grant from the National Institute for Health Research (NIHR) under its Programme Grants for Applied Research (grant no. RP-PG-0407-10098).
Chong LY, Head K, Hopkins C, et al. Saline irrigation for chronic rhinosinusitis. Cochrane Database Syst Rev. 2016;(4):CD011995.
NICE. Respiratory tract infections (self-limiting): prescribing antibiotics. CG69. London: National Institute for Health and Care Excellence; 2008.
RCS. Commissioning guide: Rhinosinusitis. London: Royal College of Surgeons of England; 2013.
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