Thank you for your inquiry. Your question is very topical.
At this time, there is no oral immunotherapy for respiratory allergy approved in the United States. The extracts that we are presently using for subcutaneous immunotherapy are not appropriate for use in oral immunotherapy because they have not been tested in this regard, and therefore we do not know what the appropriate doses or protocol would be. So, at this time, in my opinion, it is inappropriate to use oral immunotherapy.
Nonetheless, it is anticipated that oral immunotherapy will be available in the United States in the not too distant future. Several studies have shown that this therapy can be effective, and as you mentioned, it is in use in different forms in Europe. At the present time, a liquid preparation as well as a melt-away tablet are being studied, and both should go before the FDA for approval. Until which time they are approved, however, as noted, at least in my opinion, it would be inappropriate to use oral immunotherapy to treat a patient with respiratory allergy using presently available extracts approved for subcutaneous immunotherapy only.
The other option is subcutaneous immunotherapy (SCIT). It is a proven treatment which has been in use in this country for several decades.
There have been several good reviews of this topic. Copied for you below, should you wish to read further about sublingual immunotherapy, are the abstracts of two of these.
Thank you again for your inquiry and we hope this response is helpful to you.
Hum Vaccin Immunother. 2012 Oct 1;8(10). [Epub ahead of print]. Allergen immunotherapy for allergic respiratory diseases. Cappella A, Durham SR.
Section Allergy and Clinical Immunology, National Heart and Lung Institute; Imperial College; London UK.
Allergen specific immunotherapy involves the repeated administration of allergen products in order to induce clinical and immunologic tolerance to the offending allergen. Immunotherapy is the only aetiology-based treatment that has the potential for disease modification, as reflected by longterm remission following its discontinuation and possibly prevention of disease progression and onset of new allergic sensitizations. Whereas subcutaneous immunotherapy is of proven value in allergic rhinitis and asthma there is a risk of untoward side effects including rarely anaphylaxis. Recently the sublingual route has emerged as an effective and safer alternative. Whereas the efficacy of SLIT in seasonal allergy is now well-documented in adults and children, the available data for perennial allergies and asthma is less reliable and particularly lacking in children. This review evaluates the efficacy, safety and longterm benefits of SCIT and SLIT and highlights new findings regarding mechanisms, potential biomarkers and recent novel approaches for allergen immunotherapy.
Pediatr Allergy Immunol. 2008 Aug;19 Suppl 19:60-70. New visions in specific immunotherapy in children: an iPAC summary and future trends. Halken S, Lau S, Valovirta E.
HC Andersen Childrens Hospital, Odense University Hospital, Odense, Denmark.
Specific immunotherapy is indicated for confirmed immunoglobulin E-mediated airway diseases using standardized allergen products with documented clinical efficacy and safety. For decades the subcutaneous route of administration (SCIT) has been the gold standard. Recently, the sublingual immunotherapy (SLIT) has also been investigated in children. SCIT, especially with grass and birch pollens but also house dust mites, is an effective treatment in children with allergic rhinitis and asthma when a significant part of their symptoms are caused by these allergens. A long-term effect up to 12 yr after discontinuation of SCIT with timothy allergen has been shown. Efficacy and safety of SLIT in pollen allergic rhinoconjunctivitis have been demonstrated in adults. The evidence in children is a little less convincing, and more data is needed. The clinical relevance, long-term results and the size of the effect, as well as the dose, the treatment regimen and duration has not been sufficiently elaborated. It is demonstrated that SCIT has the potential for preventing the development of asthma in children with allergic rhinoconjunctivitis. Also one randomized study indicates a preventive effect of SLIT in children on the development of asthma. At present, there are no studies who clearly demonstrates either a long-term effect or a preventive effect on the development of asthma of SLIT in children. The areas with lack of evidence should be addressed in well performed prospective, randomized long-term studies both with SCIT and SLIT. This review was initiated by iPAC (international Pediatric Allergy and Asthma Consortium) and aims to review current knowledge related to specific immunotherapy in childhood, and to identify needs for future research in this field.
Phil Lieberman, M.D.