Allergic rhinitis

Overview

Background

Allergic rhinitis (perennial and seasonal) affects around 10-40% of the population worldwide, and can have a substantial health and economic impact on the community.(Sibbald 1991)

The condition can affect several organ systems, and cause many symptoms. Typical symptoms include sneezing, nasal itching, nasal blockage, and watery nasal discharge.(Lund 1994)

Other symptoms include eye symptoms (e.g. red eyes, itchy eyes, tearing), coughing, wheezing and shortness of breath, oral allergy syndrome (i.e. an itchy, swollen oropharynx on eating stoned fruits), and systemic symptoms such as tiredness, fever, a pressure sensation in the head, and itchiness.

Risk factors include a personal or family history of atopy or other allergic disorders, male sex, birth order (increased risk being seen in first born), and small family size.(Parikh 1997; Ross 1994) Allergic rhinitis may impair quality of life, interfering with work, sleep, and recreational activities.(Blaiss 1999)

The aim of conventional treatments for hay fever is to minimise or eliminate symptoms, improve quality of life, and reduce the risk of developing coexistent disease. Drug treatments include oral and topical antihistamines, oral and intranasal corticosteroids, leukotriene receptor antagonists and decongestants.

Clinical Evidence

Evidence from systematic reviews suggests that acupuncture and moxibustion may be a safe and effective treatment for allergic rhinitis with benefits over conventional medicine (Xiao 2009), that acupuncture can help to relieve symptoms of perennial rhinitis (Lee 2009) and that ear acupressure has a similar efficacy to antihistamines (Zhang 2010). However, the reviews also state that the evidence is mixed and the trials generally of poor quality and that more high-quality randomised controlled trials are needed to assess the effectiveness of acupuncture for allergic rhinitis, particularly seasonal (hay fever).(Roberts 2008; Lee 2009; Xiao 2009; Zhang 2010). Recent randomised controlled trials have found that acupuncture used as an adjunct to routine care for allergic rhinitis has clinically relevant and persistent benefits (Brinkhaus 2008) and is cost effective (Witt 2009). Such trials have also found that acupuncture is effective in the symptomatic treatment of perennial rhinitis (Xue 2007) and that active acupuncture is more effective than sham acupuncture in decreasing the symptom scores for persistent allergic rhinitis and increasing the symptom-free days (Ng 2004). (see Table below)

Potential mechanisms

In general, acupuncture is believed to stimulate the nervous system and cause the release of neurochemical messenger molecules. The resulting biochemical changes influence the body’s homeostatic mechanisms, thus promoting physical and emotional well-being. Stimulation of certain acupuncture points has been shown to affect areas of the brain that are known to reduce sensitivity to pain and stress (Hui 2010)

Acupuncture may help to relieve pain and congestion in people with allergic rhinitis by:

• regulating levels of IgE and cytokines, mediators of the allergic reaction to extrinsic allergens (Ng 2004; Rao 2006; Roberts 2008)
• stimulating nerves located in muscles and other tissues, which leads to release of endorphins and other neurohumoral factors, and changes the processing of pain in the brain and spinal cord (Pomeranz, 1987; Han 2004; Zhao 2008; Cheng 2009);
• reducing inflammation, by promoting release of vascular and immunomodulatory factors (Zijlstra 2003; Kavoussi 2007);
• enhancing natural killer cell activities and modulating the number and ratio of immune cell types (Kawakita 2008);
• increasing local microcirculation (Komori 2009), which aids dispersal of swelling.