56.3% of asthma cases are caused by allergy according to the Center for Disease Control’s National Health and Nutrition Examination Survey. Asthma is also the most common chronic childhood disease. Asthma affects more than 20 million Americans, causing 10 million out-patient visits, 500,000 hospitalizations, and more than 4,000 deaths per year.
Asthma is a chronic inflammatory disease of the lower airway with classic symptoms such as:
- Frequent respiratory infections
- Cough – can be chronic, with phlegm or dry, mild or severe. The cough often happens at night or during exercise.
- Chest tightness
- Irritated throat
Allergen exposure, respiratory infections, air pollution including tobacco smoke, and exercise — particularly in cold weather — may aggravate symptoms. Late night symptoms, emergency room visits and hospitalizations are alarming signs of asthma.
For some people, symptoms occur only a few times each year, particularly with acute exposure to mold, dust, grass, weed and tree pollens, and animal dander. For others, particularly those allergic to dust mite and mold, asthma symptoms can be experienced daily and are debilitating. Though asthma attacks can occur any time of the year, the combination of fall pollens and molds and the exchange of respiratory viruses as the school year begins yields an alarming increase in acute asthma attacks.
The only long-term way to prevent the lasting effects of asthma is to treat the underlying cause of the inflammation, such as reducing allergen exposure and treating the underlying allergic sensitivity with immunotherapy.
The long-term benefit of sublingual immunotherapy in asthmatics was clearly shown by Di Rienzo et al. A study of 60 children suffering from asthma due to dust mites showed a dramatic difference in asthma medication use between the treatment group and the control group. This benefit even lasted four to five years after treatment was discontinued.
Sublingual Immunotherapy and Asthma Research
Some of the most gratifying sublingual immunotherapy studies are those that have shown a decrease in asthma development in children. In one study (Novembre) the effect was a nearly four-fold decrease in asthma development in patients who were given sublingual immunotherapy versus control subjects. In another study (Di Rienzo) patients with asthma who improved on allergy drops still saw improvement five years after therapy ended.
In the Annals of Allergy, Asthma & Immunology September 2008, Marogna et al. published a study comparing sublingual immunotherapy vs medications only. New allergic sensitizations occurred in 34.8% of controls, and in only 3.1% of sublingual immunotherapy patients. After three years, 45% of the control group had developed intermittent or persistent asthma. 13% of SLIT patients developed asthma.
In 2013, the AHRQ study to review allergy shots to treat allergic rhinitis and asthma also showed numerous benefits from sublingual immunotherapy across multiple studies.
These studies show the benefits of treating the underlying allergy and encourage the use of sublingual immunotherapy in more patients with allergies and asthma.