Dr.  Pedro Morais Silva

Allergist-Immunologist

Allergen immunotherapy a “cure” for allergies?

HPA Magazine 9

It is estimated that in Portugal, approximately 25% of the population (around 2.5 million people) suffer from respiratory allergic diseases, such as rhinitis and bronchial asthma. This number has been increasing and practically doubled in the last 25 years, especially affecting children and adolescents.
The objective of treating respiratory allergies is to reduce the daily symptoms, in order to minimise the impact of the disease on the quality of life, as well as to eliminate the inflammation caused by the allergy.
However, despite the great efficiency of medication in controlling these diseases, it does not actually cure the allergy. This is why, when the medication is interrupted and if contact with the allergens (substances that provoke allergies, such as dust mites, pollen, animal hair, etc.) persists, the symptoms inevitably return. 

Immunotherapy, also known as “allergy shots” is another type of treatment, whose objective is to progressively accustom the organism to the substance responsible for the allergic disease. The immunotherapy process alters the immunological response of the individual over time. As a result, when patients are exposed to the allergen, they progressively suffer fewer symptoms.
This is not conventional medication. The treatment only consists of administering small, well-defined quantities of the substances an individual is allergic to. The treatment is available for most common respiratory allergens and is individual prepared for each person, in accordance to his/her allergies.
The efficiency depends very much om the adequate selection of the vaccine. Normally, it is a specialist in allergic diseases, an allergist/immunologist, who prescribes the preparations for immunotherapy. The Allergology Unit of the Hospital Particular do Algarve has a multidisciplinary team of health professionals with experience in prescribing and administering this treatment.
The decision to start this treatment depends on an experienced physician and the willingness of the patient. The treatment can be given by monthly subcutaneous injections, under medical supervision, or by drops or pills placed under the tongue, applied daily at home.
Immunotherapy is generally administered for a minimum of three to five years. After a year of treatment, the effects will be felt and the intensity of the allergic symptoms diminishd significantly, which leads to a decrease in taking other anti-allergic medications. Three years after starting the treatment, it is often no longer necessary to take daily medicine to control the allergy. Some patients become completely controlled while, in other cases, despite improvement, some symptoms persist. When the treatment is finished, the effect is normally long-lasting.
Immunotherapy is safe for people of all ages. In children and adolescents, immunotherapy has shown to help prevent the future development of allergic asthma.
In short, immunotherapy is a promising treatment for allergies and can, when applied, improve the quality of life of patients with allergic diseases and potentially be curative.