It is the administration of purified allergen extracts of whatever the person is allergic to, in gradually increasing doses, till the individual acquires ‘tolerance’ to the allergenic substance (like dust mite, fungus, grass pollen, pets, etc). In this way, the person is able to tolerate the presence of the allergen without suffering the symptoms of allergy. These are purified natural protein extracts and contain no antibiotics, anti-histaminics or steroids, and therefore are very safe, even in small children.
“immunotherapy is currently the only medical intervention that could potentially alter the natural course of allergic diseases.”
Allergen immunotherapy is the ONLY treatment that has a disease modifying effect, and not only reduces the symptoms but helps stop progress of the disease. It has long lasting benefits, even after cessation of the therapy. European Academy of Allergy and Clinical Immunology, EAACI. European declaration on immunotherapy 2011.
The concept behind immunotherapy (allergy shots or allergy tablets) is that the immune system can be desensitized to specific allergens that trigger allergy symptoms. The allergen(s) are identified through a combination of a medical evaluation performed by a trained allergist and allergy diagnostic testing (skin prick tests or allergy blood tests). Allergy immunotherapy is a proven effective treatment for allergic rhinitis, allergic asthma and stinging insect allergy. It also may be effective in some individuals with atopic dermatitis (eczema) if they have allergies to airborne allergens.
There is ample evidence globally that correct diagnosis using skin prick tests and initiation of appropriate immunotherapy can reduce the requirements of anti-histaminics, steroids and topical steroids by 60-74%. Allergen immunotherapy (AIT) is effective in alleviating allergy symptoms to a similar or even greater extent than pharmacological treatments for both asthma and allergic rhinitis; nonetheless, awareness about AIT is still poor.
Immunotherapy can potentially lead to long-lasting improvement of allergy symptoms, even upto 12 years following the stoppage of therapy and it may prevent the development of asthma and new allergies.
Indications
SLIT is indicated for IgE-mediated allergic diseases, such as
- 1] moderate-severe allergic rhinitis,
- 2] rhinoconjuctivitis, and
- 3] controlled mild-moderate allergic asthma
- 4] Few studies have tested the use of SLIT to treat food allergies, although the effectiveness of this treatment form is being further evaluated with sublingual use of extracts and oral use of whole food.
SLIT is indicated for adults and children; there are no age limitations
Contraindications
The following are contraindications to SLIT:- 1] oral ulcers /eosinophilic oesophagitis
- 2] uncontrolled asthma, and acute infections, such as a cold with a fever.
- 3] SLIT may be continued during pregnancy, but it should not be initiated during pregnancy
- 4] The use of beta-blockers should be substituted because they decrease the appropriate response to adrenaline in the case of a systemic reaction
- 5] SLIT may be carefully considered also among patients with autoimmune and immunodeficiency diseases because no evidence suggests that the use of this treatment may worsen the disease.
Is immunotherapy safe during pregnancy ?
According to international guidelines issued by most authorities like the AAAAI and the EAACI, Allergy vaccines are not started on patients who are pregnant but can be continued on patients who become pregnant while receiving it. Although current immunotherapy doses can be maintained during pregnancy, doses should not be increased until after delivery.
The literature suggests that, overall, SLIT is clinically effective in rhinoconjunctivitis and asthma, although differences exist among allergens.
The available meta-analyses are in favor of SLIT (rhinitis and conjunctivitis in adults; asthma and rhinitis in children)
Clinical efficacy and dose dependency have been demonstrated for rhinoconjuntivitis due to grass pollen in adequately powered, well-designed RDBPCs.
Some open, controlled trials suggested that the clinical efficacy of SLIT is similar to that of injection immunotherapy
Allergen immunotherapy (AIT) is effective in alleviating allergy symptoms to a similar or even greater extent than pharmacological treatments for both asthma and allergic rhinitis; nonetheless, awareness about AIT is still poor.
Efforts by patient organizations, general practitioners, non-allergist health care professionals, and pharmacists will be needed to increase the awareness of AIT among allergic patients.
