Nasal Saline Irrigation for Upper Respiratory Tract Infection and Seasonal Allergies

By Ted Wissink, MD, Megan Britton, MBBS, and Craig Schneider, MD. Dr. Wissink is Faculty in the Integrative Family Medicine Program at Maine Medical Center. Dr. Britton is a Fellow at the Integrative Family Medicine Program at Maine Medical Center and recently completed a Fellowship at the University of Arizona Center for Integrative Medicine. Dr. Schneider is Director of Integrative Medicine, Department of Family Medicine, Maine Medical Center in Portland; they report no financial relationships to this field of study.

Recently it seems that everyone from your Aunt Mildred to Oprah is spouting the merits of nasal irrigation. In this review, we attempt to sniff out fact from fiction.

Background

Nasal irrigation, also known as "jala neti" or flushing of nasal cavities with hypertonic saline solution, has been practiced for at least hundreds of years by yoga practitioners in Southern Asia and more recently has become popular around the world as an adjunctive therapy for treating nasal and sinus symptoms. It likely originated in the Ayurvedic medical tradition and descriptions and instructions for use first appeared in Western medical literature in the early 20th century.1 Saline is inserted into one nostril and allowed to drain out of the other nostril, and may be performed using low positive pressure (spray bottle), or with gravity-based pressure (neti pot with a nasal spout). The precise mechanism of action remains unknown, but several theories have been proposed including mechanical evacuation2 and improved mucociliary clearance,3 leading to reduced concentrations of inflammatory mediators such as histamine and leukotriene C4, thus reducing mucosal edema.4

Clinical Studies

This review includes studies published since 2000.

Chronic Rhinosinusitis

Several studies demonstrate significant benefit of nasal irrigation with hypertonic saline for patients with frequent sinusitis. In 2002, Rabago et al randomized 76 patients from primary care (n = 70) and otolaryngology (n = 6) clinics with histories of frequent sinusitis, defined as either two episodes of acute sinusitis or one episode of chronic sinusitis per year for two consecutive years, into intervention or control groups.5 The intervention group used daily saline irrigation for 6 months while the control group continued treatment of sinus disease in their usual manner. The primary outcomes were quality-of-life scores from a validated questionnaire, the Rhinosinusitis Disability Index (RSDI), and the Single-item Sinus-symptom Severity Assessment (SIA). Secondary outcomes were assessed every 2 weeks by recording compliance with the nasal irrigation (daily diary) along with the presence or absence of sinus symptoms, antibiotic use, and nasal spray use. After 6 months, the intervention group reported adherence to nasal irrigation during 87% of the study, and their questionnaire scores improved significantly as compared to the control group (P < 0.001 for both measures). The number needed to treat to achieve a 10% improvement at 6 months was 2. The nasal irrigation intervention group reported fewer periods of sinus-related symptoms, less antibiotic use, and 93% reported overall improvement of sinus-related quality of life. None reported worsening and side effects were minor and infrequent.

Rabago et al continued to study the patients above in an uncontrolled 12-month follow-up that combined 40 participants from the intervention group from the previous study and 14 from the control group (all patients used nasal irrigation in this study).6 They again followed the RSDI and the Sino-nasal Outcomes Test (SNOT-20). Secondary outcome measures were frequency and pattern of nasal irrigation use, side effects, and participant satisfaction. Prior intervention group RSDI scores continued to improve (P < 0.001), and their SNOT-20 scores remained stable. Prior control participants' RSDI scores improved similarly to the intervention group (P < 0.001) and the SNOT-20 scores decreased significantly (P = 0.05); and as for anyone with nasal congestion, the less SNOT (scores in this case) the better. Mean nasal irrigation use for all participants was 2.4 times per week. Satisfaction was high and side effects were minor.

A third study by Pynnonen et al compared isotonic saline nasal irrigation with saline nasal sprays for the treatment of chronic nasal/sinus symptoms.7 A total of 127 adults 18 years or older were enrolled. Each self-reported one or more of the following symptoms 4 or more days per week in the preceding 2 weeks if they had been present for at least 15 of the previous 30 days: nasal congestion, nasal dryness or crusting, or thick nasal discharge. Excluded were patients with recent sinus surgery, respiratory infection within the preceding 2 weeks, or who had previously used either of the study interventions. Participants were randomly assigned to either irrigation or spray and asked to do the assigned treatment twice daily for 8 weeks. Outcomes were measured at 2, 4, and 8 weeks via mail-in survey, including the SNOT-20 measure of symptom severity, a symptom frequency questionnaire, and a medication diary documenting compliance and use of prescription and nonprescription medications for nasal and sinus-related symptoms. Baseline SNOT-20 scores were similar in the two groups, and both groups showed significantly lower scores at 8 weeks. The irrigation group scores declined significantly more than the spray group at 8 weeks (P = 0.002). Symptom frequency also decreased significantly in both groups but more in the irrigation group (P = 0.01). There was no difference in medication (both oral and nasal) use between groups, but a significant decrease in medication use was noted for both groups compared to baseline. Compliance was higher in the spray group (97%, 93%, and 93%) than the irrigation group (92%, 81%, and 79%) at weeks 2, 4, and 8, respectively (P = 0.03).

Recently, an unpublished study presented at the American College of Allergy, Asthma, and Immunology Annual Meeting in Miami (2009) has cast some doubt upon the benefit of nasal saline irrigation for prevention of sinusitis.8 The authors followed 68 people who used nasal saline irrigation for 12 months and then discontinued use for another 12 months. They reported a reduction in number of cases of sinusitis by 62.5% during the discontinuation phase. Researchers then compared the rates of sinusitis among the discontinuation group with another group of 24 adults using daily nasal saline irrigation for 12 months. Again, they found significantly higher (50%) rates of sinusitis among saline irrigation users than nonusers. The authors hypothesize that because nasal mucus acts as a first line of defense against infections, long-term nasal saline irrigation may interfere with this natural immune barrier. Although use of a neti pot for nasal saline irrigation may temporarily improve sinus infection symptoms, they say "its daily long-term use may result in an increased frequency of acute [sinusitis] by potentially depleting the nose of its immune blanket of mucus."

Seasonal Allergies in Children

In 2005, Garavello et al studied the relationship between nasal irrigation used during the seasonal allergy period and symptoms of allergic rhinoconjunctivitis in a pediatric population.9 Children with seasonal grass pollen rhinoconjunctivitis were randomized to three times daily nasal irrigation with hypertonic saline during the 7 weeks of pollen season. Subjects in the treatment group were allowed to use oral antihistamines as needed. The mean rhinoconjunctivitis symptom score in the active group was reduced (graph shows approximately 3.5 vs. 10 in the control group) during the pollen period. Statistical significance was reported in weeks 6 and 7. A statistically significant reduction in antihistamine use among the treatment group was reported in 5 of the 7 weeks (0-2 in the treatment group and 2-5 in the control group). No adverse effects were reported, and the treatment was thought to be tolerable, inexpensive, and effective. Unfortunately, the authors did not report results numerically, and no P-values or confidence intervals are provided.

In 2003, Garavello et al evaluated the use of hypertonic saline nasal irrigation in the prevention of seasonal allergic rhinitis-related symptoms in pediatric patients.10 Twenty children with allergic seasonal rhinitis to Parietaria sp. were randomized to nasal irrigation with hypertonic saline three times a day for the entire pollen season (6 weeks). Mean daily rhinitis scores were calculated (based on nasal itching, rhinorrhea, nasal obstruction, and sneezing) and patients were allowed to use oral antihistamines as needed. In the irrigation group, the mean daily rhinitis score was reduced during 5 weeks of the study period, and this became statistically significant at weeks 3-5. Graphs demonstrate rhinitis scores of 11-14 in the control group and 4-6 in the treatment group. The authors report less oral antihistamine use in the treatment group (0-2 tablets per week) than for controls (2-5 tablets per week) and this was statistically significant in weeks 3, 4, and 6. Unfortunately, numerical results, P-values, and confidence intervals are not provided. Nasal irrigation was reported to be tolerable, inexpensive, and effective in this trial.

The children in both the 2003 and 2005 studies ranged in age from 6 to 12 years.

Pediatric Upper Respiratory and Influenza Infection

In 2008, Slapak et al studied 401 children ages 6-10 years with uncomplicated cold and flu. Subjects were randomized to standard medication (antipyretics, nasal decongestants, mucolytics, and/or systemic antibiotics) or nasal irrigation with modified seawater.11 The saline solution used was a commercially available isotonic product processed from Atlantic Ocean seawater (Physiomer; Goemar Laboratoire de la Mer, Saint Malo, France). Subjects used irrigation six times per day in the acute setting and three times per day for prevention and were observed for 12 weeks. Patients in the nasal irrigation group showed lower symptom scores (sore throat, cough, nasal obstruction) and decreased use of medication (antipyretics, 9% vs. 33%; nasal decongestants, 5% vs. 47%; mucolytics, 10% vs. 37%; and systemic anti-infectives, 6% vs. 21%). Nasal irrigators also reported fewer days with illness (31% vs. 75%), school absence (17% vs. 35%), and complications (8% vs. 32%). The authors reported faster resolution of nasal symptoms during acute illness and less frequent reappearance of rhinitis subsequently among children in the nasal irrigation group.

Adverse Effects

Nasal irrigation appears to be well tolerated. Reported side effects include post-treatment drainage, nasal irritation, nasal burning, bitter taste, and epistaxis. However, adherence-to-treatment rates are high, suggesting few side effects severe enough to lead to discontinuation of treatment. In our experience, irritation or burning can be eliminated with reduction of the irrigation solution salinity or buffering with baking soda. Post-treatment positioning such as forward flexion at the waist along with head rotation and exhalation through the nose seems to augment drainage of salt water out of the nasal passage. This may minimize the sensation of continued drainage experienced by some users after using nasal irrigation.

Discussion

For treatment of chronic rhinosinusitis, most recent studies show statistically significant improvement in sinus symptoms and quality of life along with reduced antibiotic and nasal spray medication use. In general, the studies showed limited adverse effects and high patient compliance and satisfaction.

Whether the statistical improvement in symptoms translates into clinical benefit was addressed by Pynnonen et al. In their study the improvement in SNOT-20 scores ranged from 12.2 to 16.2 points.12 In comparison, a study that followed patients after sinus surgery showed an improvement of 19-22 points and patients with severe polyposis treated with oral prednisone improved by 10 points.13

Study strengths include generizability and practicality, since they focused on community-based populations with reported chronic sinus symptoms that are commonly seen by primary care providers. A major challenge is the inability to blind subjects or researchers to a physical treatment like nasal irrigation. The studies evaluating chronic rhinosinusitis also did not have adequate power to evaluate subgroups, such as patients with allergic rhinitis, nasal polyposis, cystic fibrosis, or anatomic problems causing congestion.

With respect to chronicity of treatment, the negative study presented at a recent conference is interesting. It showed that possible long-term use (> 12 months) may not be recommended. More research is needed in this area before official recommendations can be given, but caution should be advised regarding long-term treatment for now.

Although supportive, the pediatric research on nasal irrigation also suffers from the above mentioned methodological weaknesses and more. For example, Garavello (in both 2003 and 2005) did not report numerical results, P-values, or confidence intervals. The studies were not blinded, and no placebo was used. The number of subjects were small, and treatment periods brief (ranging from 6 to 7 weeks). Slapak's study included large numbers of subjects, was randomized and partially blinded (physicians were aware of which patients used nasal wash and their assignment to particular groups, but were not informed about the composition and device used in these groups since the bottles were not labeled), and reported clear results. However, the study used six times a day irrigation, which is not the standard use pattern and likely to suffer from poor adherence in the general population.

Conclusion

Most recent published research supports the use of nasal saline irrigation for the prevention and treatment of chronic rhinosinusitis, pediatric seasonal allergies, colds, and flus. Further study is needed to determine the most effective solution for nasal irrigation (hypertonic saline solution, buffered saline solution, Dead Sea salts, etc.), frequency of irrigation, and duration of treatment in both acute and preventive settings.

Recommendation

Based on the positive outcomes and low side effect reports in the recent studies on saline nasal irrigation, we recommend it for allergic rhinitis, colds, and chronic sinusitis for patients ages 6 years and older. People can mix their own saline with table salt or purchase premade packets of salt. The most effective salinity level is undetermined, so we recommend using 0.25-0.5 teaspoons of salt for every 8 ounces of lukewarm tap water and using 8 ounces of water for each nasal cavity irrigated. Decreasing the amount of salt can help if a patient experiences irritation. If table salt is used rather than proprietary blends, more time may be necessary for it to completely dissolve in the water. Published studies suggest a good safety profile, but vigilance to the possibility of harm with regular, long-term use of nasal irrigation is recommended until clarified by further research.

References

1. Rabago D, Zgierska A. saline nasal irrigation for upper respiratory conditions. Am Fam Physician 2009;80: 1117-1119.

2. Rabago D, et al. Qualitative aspects of nasal irrigation use by patients with chronic sinus disease in a multimethod study. Ann Fam Med 2006;4:295-301.

3. Homer JJ, et al. The effect of hypertonicity on nasal mucociliary clearance. Clin Otolaryngol Allied Sci 2000;25:558-560.

4. Tomooka LT, et al. Clinical study and literature review of nasal irrigation. Laryngoscope. 2000; 110:1189-1193.

5. Rabago D, et al. Efficacy of daily hypertonic saline nasal irrigation among patients with sinusitis: A randomized controlled trial. J Fam Pract 2002;51: 1049-1055.

6. Rabago D, et al. The efficacy of hypertonic saline nasal irrigation for chronic sinonasal symptoms. Otolaryngol Head Neck Surg 2005;133:3-8.

7. Pynnonen MA, et al. Nasal saline for chronic sinonasal symptoms: A randomized controlled trial. Arch Otolaryngol Head Neck Surg 2007;133:1115-1120.

8. Nsouli TM, et al. Long-term use of nasal saline irrigation: Harmful or helpful? Ann Allergy AsthmaImmunol 2009;103:A27.

9. Garavello W, et al. Nasal rinsing with hypertonic solution: An adjunctive treatment for pediatric seasonal allergic rhinoconjunctivitis. Int Arch Allergy Immunol 2005;137:310-314.

10. Garavello W, et al. Hypersaline nasal irrigation in children with symptomatic seasonal allergic rhinitis: A randomized study. Pediatr Allergy Immunol 2003: 14:140-143.

11. Slapak I, et al. Efficacy of isotonic nasal wash (seawater) in the treatment and prevention of rhinitis in children. Arch Otolaryngol Head Neck Surg 2008; 134:67-74.

12. Colclasure J, et al. Endoscopic sinus surgery in patients older than sixty. Otolaryngol Head Neck Surg 2004;131:946-949.

13. Woodworth B, et al. Alterations in eotaxin, monocyte chemoattractant protein-4, interleukin-5, and interleukin-13 after systemic steroid treatment for nasal polyps. Otolaryngol Head Neck Surg 2004;131: 585-589.