World Allergy Day is celebrated on 8 July and is a joint initiative of the World Health Organization (WHO) and the World Allergy Organization (WAO) to raise awareness of the importance of treating and preventing allergies.
Allergy results from an excessive response of the immune system (hypersensitivity reaction) to contact with an external stimulus, normally tolerated by the general population.
Allergic diseases affect all age groups, from children to the elderly, and are often chronic pathologies that can affect several organs. In recent decades, there has been an increase in the incidence and prevalence of allergic diseases, which may be a consequence of genetic characteristics, but especially of environmental and lifestyle changes.
In Portugal, and according to the Portuguese Society of Allergology and Clinical Immunology (SPAIC), it is estimated that allergies affect approximately one third of the population.
There are several allergic pathologies. Rhinitis is the most prevalent allergic disease and currently affects around 30% of Portuguese people, 40% of whom have concomitant asthma. Anaphylaxis is the most serious form of allergic disease and is a medical emergency as it is a severe and potentially fatal systemic hypersensitivity reaction. In relation to drug allergy, it is estimated that about 7% of the general population has already had a hypersensitivity reaction to at least one drug. Among the drugs most frequently involved in these reactions are non-steroidal anti-inflammatory drugs (NSAIDs) and antibiotics. With the appearance of new therapeutic tools in Oncology, there has also been an increase in the incidence of reactions to chemotherapy and biological therapies. When investigating a drug hypersensitivity reaction, it is extremely important to guide patients, documenting their reactions; as well as offering them therapeutic alternatives, inducing tolerance to drugs that cause allergic reaction, whenever possible.
The incidence of food allergy is also increasing in all age groups. In food allergy, mild reactions may evolve into severe situations of anaphylaxis and, therefore, it is essential to refer patients with a clinical history suggestive of food allergy to an Immuno-allergology consultation.
The area of Allergology and Immunology has, in recent years, grown towards a more stratified and personalized approach to allergic and immunological diseases. The emergence of “diagnosis by molecular components”, for example, is one of the tools that has contributed to precision medicine. This method allows identifying allergenic molecules involved in the etiological process of allergic diseases and a choice of immunotherapy that is more adapted to the individual profile of each patient. Furthermore, the detailed knowledge of the endotypes of allergic diseases has contributed to the emergence of biological therapies, produced through biotechnology methods and formulated to inactivate specific mechanisms of the disease.
Thus, currently in Immuno-allergology, in addition to the centuries-old allergen immunotherapy that is the only therapy capable of modifying the natural history of allergic diseases, we have recent and powerful therapeutic tools that have revolutionized the treatment of several serious, immune-mediated diseases, such as asthma, chronic urticaria, eczema and rhinosinusitis with nasal polyposis.
Thus, the celebration of this date is, in my personal and professional opinion, extremely important so that we do not forget that allergic diseases, due to their high prevalence and morbidity, constitute an important public health problem.
Joana Cosme
Immunologist-allergist
CHULN's Immuno-allergology Service
