Research Activities, May 2013
Allergen-specific immunotherapy is safe and effective for treating nasal allergies and mild asthma
Comparative Effectiveness Research
A new research review from AHRQ finds at least a moderate level of evidence that allergen-specific immunotherapy is effective and safe for the treatment of nasal allergies and mild asthma in both adults and children. This immunotherapy is either injected under the skin (subcutaneous) or administered in an off-label mechanism via placement under the tongue (sublingual). This type of therapy is typically recommended for people whose conditions cannot be controlled by other strategies, who cannot tolerate their medications, or who do not comply with chronic medication regimens.
The review finds a high strength of evidence that subcutaneous allergen-specific immunotherapy reduces asthma, nasal and conjunctivitis symptoms, as well as the use of asthma medications, and improves rhinoconjunctivitis-specific quality of life. There is a moderate strength of evidence that subcutaneous immunotherapy reduces the use of rhinoconjunctivitis medication.
Similarly, there is a high strength of evidence that sublingual immunotherapy reduces asthma symptoms, and a moderate level of evidence that it reduces nasal and conjunctivitis symptoms and medication usage, and improves allergy-specific quality of life. In the United States, there are currently no sublingual forms of immunotherapy approved by the Food and Drug Administration, though researchers and physicians in the United States are exploring the off-label use of subcutaneous aqueous allergens for sublingual desensitization. Because there are fewer pediatric studies than adult studies, the evidence to support the use of allergen-specific immunotherapy in children is somewhat weaker than the evidence supporting its use in adults. Additional studies may provide more insight into the effectiveness and safety of allergen immunotherapy in the pediatric population.
Based on the current evidence, it is unknown whether one route of administration is more effective or safer than the other. Additional studies that directly compare subcutaneous versus sublingual therapies would be required to answer this question. Allergic rhinitis is a widespread clinical problem, estimated to affect 20 to 40 percent of the population in the United States. The prevalence of asthma in the general U.S. population is approximately 9 percent, and approximately 62 percent of individuals with asthma have evidence of atopy (i.e., one or more positive specific IgE levels that indicate allergies).
These findings are available in the research review, Allergen-Specific Immunotherapy for the Treatment of Allergic Rhinoconjunctivitis and/or Asthma: Comparative Effectiveness Review at http://go.usa.gov/TKcT.