Seasonal Allergies and Complementary Health Approaches: What the Science Says
Clinical Guidelines, Scientific Literature, Info for Patients:
Seasonal Allergies and Complementary Health Approaches
Saline Nasal Irrigation
There is some evidence to suggest that saline nasal irrigation may modestly improve some seasonal allergy symptoms.
What Does the Research Show?
The available data on efficacy of saline nasal irrigation for seasonal allergy symptoms consist of several randomized controlled trials in both adults and children, as well as a systematic review and meta-analysis.
- A 2012 systematic review and meta-analysis of 10 studies found that saline nasal irrigation administered regularly over a period of up to 7 weeks was observed to have beneficial effects on nasal symptoms, reduction in medicine consumption, acceleration of mucociliary clearance time, and quality of life in adults and children with allergic rhinitis.
- A 2012 review of nasal saline irrigation in the management of sinonasal disease found that nasal saline irrigation appears to demonstrate some modest clinical benefits.
- Nasal irrigation is generally safe; however, neti pots and other rinsing devices must be used and cleaned properly.
- Most important is the source of water that is used with nasal rinsing devices. According to the U.S. Food and Drug Administration, tap water that is not filtered, treated, or processed in specific ways is not safe for use as a nasal rinse. Some tap water contains low levels of bacteria and protozoa, including amoebas, which can stay alive in nasal passages and cause potentially serious or fatal infections.
- Improper use of neti pots may have caused two deaths in 2011 in Louisiana from a rare brain infection that the state health department linked to tap water contaminated with an amoeba called Naegleria fowleri.
Butterbur (Petasites hybridus)
Some studies of butterbur root or leaf extracts suggest that they may be helpful for symptoms of hay fever (allergic rhinitis), but the data are not convincing. Importantly, there are some safety concerns associated with its use.
What Does the Research Show?
The available data on efficacy of butterbur for seasonal allergies consist of only a few rigorous randomized controlled trials.
- Findings from a 2007 systematic review of six randomized controlled trials suggest that butterbur is superior to placebo or similarly effective compared with nonsedative antihistamines for intermittent allergic rhinitis. However, firm conclusions could not be drawn because three of the large trials reviewed received financial support from a manufacturer of butterbur, which represents a conflict of interest.
- A 2003 review of several modalities used to treat ocular allergies found that in one study of 125 participants, butterbur was just as effective as a commonly used oral antihistamine for itchy eyes.
- Some butterbur products contain chemicals called pyrrolizidine alkaloids (PAs). PAs can damage the liver, lungs, and blood circulation, and possibly cause cancer. Only butterbur products that have been processed to remove PAs and are labeled or certified as PA-free should be considered for use.
- Some countries have withdrawn butterbur products from the market because of concerns about liver toxicity.
- Several studies, including a few studies of children and adolescents, have reported that PA-free butterbur products seem to be safe when taken by mouth in recommended doses for up to 16 weeks. However, some products claiming to be PA-free may not in fact be. For example, Petadolex is marketed as a PA-free butterbur product, but it has been associated with liver damage in some people, suggesting that it may have had PAs. Also, the safety of longer-term use of butterbur has not been established.
- Butterbur products with PAs should not be used during pregnancy or while breastfeeding because they may cause birth defects or liver damage. Little is known about whether it’s safe to use PA-free butterbur during pregnancy or while breastfeeding.
- PA-free butterbur is generally well tolerated but can cause side effects such as belching, headache, itchy eyes, diarrhea, breathing difficulties, fatigue, upset stomach, and drowsiness.
- Butterbur may cause allergic reactions in people who are sensitive to plants such as ragweed, chrysanthemums, marigolds, and daisies.
There is no convincing scientific evidence that honey relieves seasonal allergies.
What Does the Research Show?
The available data on efficacy of honey for seasonal allergy symptoms consist of only a few randomized controlled trials.
- A 2011 randomized controlled pilot study of 44 patients with physician-diagnosed birch pollen allergy found that patients who used pre-seasonal birch pollen honey had significantly better control of their symptoms compared to those on conventional allergy medication, and they had marginally better control of their symptoms compared to those using regular honey. However, these results should be regarded as preliminary.
- Eating honey is generally safe; however, children under 1 year of age should not eat honey due to the potential risk of contracting Clostridium botulinum. People who are allergic to pollen may also be allergic to honey.
There is some limited evidence that suggests that probiotics may improve some symptoms, as well as quality of life, in patients with allergic rhinitis, but overall, the data on probiotics and allergic rhinitis is inconsistent and effects may vary from one probiotic formulation to another.
What Does the Research Show?
The available data on efficacy of probiotics for allergic rhinitis consist of several systematic reviews and meta-analyses of small randomized controlled trials with a high degree of heterogeneity.
- A 2015 systematic review of 11 randomized controlled trials concluded that current evidence is not sufficiently strong to verify a preventive role of probiotics in allergic rhinitis, but probiotics may improve the overall quality of life and nasal symptom scores. Because available data are only from a small number of studies with a high degree of heterogeneity, routine use of probiotics for prevention and treatment of allergic rhinitis cannot be recommended.
- A 2015 systematic review and meta-analysis of 23 studies involving a total of 1,919 patients concluded that probiotics may be beneficial in improving symptoms and quality of life in patients with allergic rhinitis; however, current available evidence is limited due to study heterogeneity and variable outcome measures.
- A 2016 review of probiotics for allergy prevention concluded that to date, expert bodies do not generally recommend probiotics for allergy prevention; however, the review notes that World Allergy Organization guidelines suggest considering using probiotics in pregnant people, during breastfeeding, and/or for the infant if at high risk of developing allergic disease.
- A 2013 randomized controlled trial of 60 patients with allergic rhinitis examined the effects of probiotic consumption (Lactobacillus casei Shirota) on clinical and immunological parameters of seasonal allergic rhinitis in an out-of-season single nasal allergen challenge. Results of the study showed that daily oral supplementation with L. casei Shirota modified some parameters of allergic inflammation at the nasal mucosa but there were no significant changes of clinical symptoms of seasonal allergic rhinitis.
- In healthy people, probiotics usually have only minor side effects, if any. However, in people with underlying health problems, serious complications such as infections have occasionally been reported.
Mind and Body Practices
There are data from some randomized controlled trials that suggest that acupuncture may improve some symptoms of allergic rhinitis, as well as quality of life.
What Does the Research Show?
The available data on the efficacy of acupuncture for allergic rhinitis consist of several reviews and meta-analyses, as well as clinical practice guidelines issued in 2015 by the American Academy of Otolaryngology.
- Clinical practice guidelines issued in 2015 by the American Academy of Otolaryngology include the following recommendation: “Clinicians may offer acupuncture, or refer to a clinician who can offer acupuncture, for patients with allergic rhinitis who are interested in nonpharmacologic therapy.”
- A 2015 systematic review and meta-analysis of 13 studies involving a total of 2,365 participants found that compared with a control group, the acupuncture treatment group had significant reductions in nasal symptom scores, medication scores, and serum IgE, and an increase in quality of life scores.
- A 2015 review concluded that there are high-quality randomized controlled trials that demonstrate efficacy for acupuncture in the treatment of both seasonal and perennial allergic rhinitis; smaller studies show some preliminary benefit of acupuncture when compared with antihistamines, but these had some methodological limitations.
- Relatively few complications from the use of acupuncture have been reported. Still, complications have resulted from inadequate sterilization of needles and from improper delivery of treatments. A 2015 systematic review and meta-analysis examined the safety and efficacy of acupuncture for allergic rhinitis and concluded that the meta-analysis suggests that acupuncture could be a safe and valid treatment option for patients with allergic rhinitis.
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- Guo R, Pittler MH, Ernst E. Herbal medicines for the treatment of allergic rhinitis: a systematic review. Ann Allergy Asthma Immunol. 2007;99(6):483–495.
- Hermelingmeier KE, Weber RK, Hellmich M, et al. Nasal irrigation as an adjunctive treatment in allergic rhinitis: a systematic review and meta-analysis. Am J Rhinol Allergy. 2012;26(5):e119–125.
- Ivory K, Wilson AM, Sankaran P, et al. Oral delivery of a probiotic induced changes at the nasal mucosa of seasonal allergic rhinitis subjects after local allergen challenge: a randomised clinical trial. PLoS One. 2013;8(11):e78650.
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- Peng Y, Li A, Yu L, et al. The role of probiotics in prevention and treatment for patients with allergic rhinitis: a systematic review. Am J Rhinol Allergy. 2015;29(4):292–298.
- Saarinen K, Jantunen J, Haahtela T. Birch pollen honey for birch pollen allergy—a randomized controlled pilot study. Int Arch Allergy Immunol. 2011;155(2):160–166.
- Seidman MD, Gurgel RK, Lin SY, et al. Clinical practice guideline: allergic rhinitis. Otolaryngol Head Neck Surg. 2015;152(1 Suppl):S1-S43.
- Taw MB, Reddy WD, Omole FS, et al. Acupuncture and allergic rhinitis. Curr Opin Otolaryngol Head Neck Surg. 2015;23(3):216–220.
- West CE. Probiotics for allergy prevention. Benef Microbes. 2016;7(2):171–179.
- Xue CC, English R, Zhang JJ, et al. Effect of acupuncture in the treatment of seasonal allergic rhinitis: a randomized controlled clinical trial. Am J Chin Med. 2002;30(1):1–11.
- Xue CC, Zhang AL, Zhang CS, et al. Acupuncture for seasonal allergic rhinitis: a randomized controlled trial. Ann Allergy Asthma Immunol. 2015;115(4):317–324.e1.
- Zajac AE, Adams AS, Turner JH. A systematic review and meta-analysis of probiotics for the treatment of allergic rhinitis. Int Forum Allergy Rhinol. 2015;5(6):524–532.
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