A scientific review of 63 released studies affirms that putting small amounts of purified grasses, ragweed, dust mites, pollen and mold, in liquid drops under the tongue is a safe and effective alternative to weekly injections of those allergens or the use of other medications, in treating symptoms of allergies and allergic asthma in some people.
Results of the evaluation, conducted by researchers at Johns Hopkins, are contained in a report released in the Journal of the American Medical Association online 27 March. The report will be believed to be the largest synopsis of its kind, reviewing previous research comparing various therapies designed to stop the wheezing, sneezing and runny nose that accompany allergic rhinoconjunctivitis and allergic asthma, researchers say.
Specifically, the Johns Hopkins team analysed 63 studies, involving several 5, 131 participants, almost all in Europe, where allergy drops, or so-called sublingual immunotherapy, have been widely available for nearly two decades. Sublingual therapies never have been approved for use by the US Food and Drug Administration, but physicians in the United States do use the drops “off-label” for some patients.
Within eight of 13 studies examined, researchers found what they say will be “strong evidence” that drop treatment produced a 40 percent or greater reduction in coughing, wheezing, and tightness in the chest compared with additional treatments, including inhaled steroids.
In nine of 36 studies comparing allergy drops to other allergy treatments, including antihistamines and nasal steroid sprays, researchers discovered that allergy drops produced a 40 percent or greater reduction in symptoms of runny nose, sneezing and nasal congestion, results which they describe as “moderate evidence” in support of using sublingual immunotherapy.
“Our findings are clear evidence that sublingual immunotherapy in the form of allergy falls are an effective potential treatment strategy to millions of Americans suffering from allergic asthma and allergic rhinoconjunctivitis, ” states senior study investigator Sandra Lin, MD.
According to Lin, an associate professor of otolaryngology-head and neck surgery at the Johns Hopkins University School of Medicine, allergy drops are more convenient for many people because they can be taken at home, and allow such individuals to avoid the discomfort and travel time needed for regularly scheduled trips to the physician’s office to have an allergy shot. Lin says that, according to current estimates, as many as forty percent of Americans suffer from some type of allergic rhinitis or allergic asthma.
Lin cautions that drop therapies may not be for all patients of allergic rhinoconjunctivitis and allergic asthma, but that many will want to consider the risks and benefits of sublingual immunotherapy before deciding on long-term treatment options.
Study funding was provided by the US Agency for Healthcare Study and Quality. The corresponding offer number is HHSA 290-2007-10061.
(Source: Johns Hopkins University: Journal of the American Medical Association)