Subcutaneous allergen immunotherapy adverse events vary significantly depending on different allergenic extracts and the application of different allergen immunotherapy schedules.Allergen immunotherapy schedules include the "cluster" approach, which involves administering several doses sequentially in a single day; a "conventional" approach, which involves incrementally increasing the dose over approximately 15 weeks; and the "rush" approach, which involves administering incremental doses at intervals of 15–60 minutes over 1–3 days).It is challenging to perform an adequate risk assessment on the use of subcutaneous allergen immunotherapy compared to other forms of allergen immunotherapy administration due to the variability of immunotherapy schedules and further research is required. Sublingual
Sublingual immunotherapy involves putting drops or a tablet of allergen extracts under the tongue, which are then absorbed through the lining of the mouth. Sublingual immunotherapy has been demonstrated to be effective against rhinoconjuctivitis and asthma symptoms. This effectiveness, however, varies depending on the type of allergen. The strongest evidence for the efficacy of sublingual immunotherapy comes from studies that used grass allergens or mite allergens to alleviate allergic rhinitis symptoms; the evidence shows modest improvement.Sublingual immunotherapy is used to treat allergic rhinitis, often from seasonal allergies, and is typically given in several doses over a 12-week period. It works best when given 12 weeks before the start of the pollen season. The first dose is given by a physician to monitor for any rare reactions or anaphylaxis. Subsequent doses can be taken at home which makes this a convenient alternative to subcutaneous immunotherapy.
As of 2011, OIT was under investigation as a treatment for a variety of common food allergies including peanuts, milk, and eggs. Studies involving OIT have shown desensitization towards the allergen. However, there are still questions about longevity of tolerance after the study has ended. However, almost every study has excluded people with severe allergen-induced anaphylaxis.One approach being studied is in altering the protein structure of the allergen to decrease immune response but still induce tolerance. Extensive heating of some foods can change the conformation of epitopes recognized by IgE antibodies. In fact, studies show that regular consumption of heated food allergens can speed up allergy resolution. In one study, subjects allergic to milk were 16x more likely to develop complete milk tolerance compared to complete milk avoidance. Another approach regarding changes in protein is to change specific amino acids in the protein to decrease recognition of the allergen by allergen-specific antibodies.Another approach to improving oral immunotherapy is to change the immune environment to prevent TH2 cells from responding to the allergens during treatment. For example, drugs that inhibit IgE-mediated signaling pathways can be used in addition to OIT to reduce immune response. In 1 trial, the monoclonal antibody omalizumab was combined with high-dose milk oral immunotherapy and saw positive results. Several other trials are also currently being done combining omalizumab with OIT for a variety of food allergens. FAHF-2, a Chinese herbal mixture, has shown positive effects on the immune system and has been shown to protect mice from peanut-induced anaphylaxis.