Allergen Immunotherapy - Background

Background

Allergic rhinitis (an allergic inflammation of the nasal airways) is an extremely common disorder. For example in the UK 1 in 5 people have allergic rhinitis with approximately 50 percent of those with allergic rhinitis being allergic to grass pollen. Over half of people receiving symptom based treatments report that they benefit poorly or only partially from symptomatic based treatments. For these patients immunodesensitisation therapy can be recommended. Subcutaneous injection based immunotherapy is one effective route but is complicated by rare but serious side effects. As a result of these rare but serious side effects the sublingual route for allergen vaccination immunotherapy is gaining increasing popularity among allergy specialists due to its lack of serious side effects.

Immunotherapy administered through cutaneous injections or sublingually has substantial empirical support. Numerous research articles and several meta-analytic studies support its clinical effectiveness. Immunotherapy can lead to a substantial decline in allergen symptomatology leading to a significant improvement in quality of life for allergy sufferers. Repeated courses of immuno-desensitisation leads to further reduction in allergy disease severity. Immunotherapy is superior to antihistamines and topical steroids in reducing severity of allergy symptoms and has been found to be a cost effective treatment strategy. Immunotherapy results in less time taken off work compared to those who rely solely on symptomatic relieving medications. In the case of grass allergy immunotherapy the pollen from the grass species used has strong cross reactivity between the various grass species thus meaning that treatment leads to desensitisation to all grass species.

Sublingual specific immunotherapy has the benefit of allowing treatment to be carried out in the home environment and has been found to be a cost effective treatment strategy for allergic disorders. Sublingual immunotherapy cost effectiveness is significantly increased due to the reduced number of medical visits compared to those receiving subcutaneous injection based immunotherapy. For example, those receiving subcutaneous injections make almost seven times more visits than those receiving home based sublingual immunotherapy, as those receiving subcutaneous injections require frequent visits to doctors to receive their regular injections. Furthermore the sublingual route appears to be as effective as the subcutaneous route in trials of grass allergy.