Trends in the Epidemiology of Allergic Diseases of the Airways in Children Growing Up in an Urban Agglomeration

The prevalence of asthma and allergies among children has become an increasing problem in the last few decades. Data on the population of children and adolescents, especially living in polluted cities, are limited and based on studies carried out in small groups. In our study, we analyzed the incidence of asthma and allergic rhinitis between 2014 and 2018. We analyzed data collected from nearly 30,000 children aged seven to eight and adolescents aged 16–17, which allowed us to assess the frequency of allergic diseases in the population of children and youth in Krakow. More than 40% of respondents reported allergic symptoms, and nearly 50% of them were not diagnosed and treated. In the group of seven- and eight-year-olds with a positive history of allergies, 52% had allergic rhinitis and 9.1% had asthma. In the group of 16–17-year-olds, allergic rhinitis was diagnosed in 35.8%, while asthma was found in 4.9% of cases. The results obtained over the course of 10 years has shown the reduction in the frequency of asthma (from 22% in the case of asthma in both age groups) and allergic rhinitis cases (from 63.9% in adolescents). In our opinion, this can be considered a positive effect of the preventive measures taken in Kraków after 2010. Although there is still a higher incidence of allergic diseases among children and young people living in urban areas compared to rural areas, the trend apparently has reversed for some diseases.

Hypersensitivity to polyethylene glycol (PEG)

The need for mass population vaccination against Covid-19 poses a public health problem. Allergic symptoms occurring after the 1st dose of the vaccine may result in resignation from the administration of the 2nd dose. However, the majority of patients with mild and/or non-immediate symptoms may be safely vaccinated. The only absolute contraindication to administration of the vaccine is an anaphylactic reaction to any of its ingredients. Polyethylene glycol (PEG), widely used as an excipient in various vaccines, is considered the primary cause of allergic reactions associated with administration of Comirnaty (Pfizer/BioNTech) and Covid-19 Vaccine (Moderna) vaccines. However, hypersensitivity to PEG reported to date seems very rare, considering its widespread use in multiple everyday products, including medicines and cosmetics. In the paper, current literature data describing mechanisms of hypersensitivity reactions to PEG, their clinical symptoms and diagnostic capabilities are presented. Undoubtedly, the issue of hypersensitivity to PEG warrants further research, while patients with the diagnosis require individual diagnostic and therapeutic approach.

Component-resolved diagnosis (CRD) of food anaphylaxis

Anaphylaxis is an increasing problem in public health. The food allergens (mainly milk, eggs, and peanuts) are the most frequent cause of anaphylaxis in children and youth. In order to define the cause of anaphylaxis, skin tests, the determination of the concentration of specific IgE in the blood and basophil activation test are conducted. In vitro tests are preferred due to the risk of allergic response during in vivo tests. Component-resolved diagnosis (CRD) is an additional tool in allergology, recommended in the third level of diagnostics when there are diagnostic doubts after the above mentioned tests have been carried out. The paper presents 3 cases of patients with anaphylactic response, and the application of CRD in these patients helped in planning the treatment. Patient 1 is a 4-year-old boy with diagnosed atopic dermatitis and bronchial asthma reported an anaphylactic shock at the age of seven months caused by cow's milk and the exacerbation of bronchial asthma after eating some fruit. Patient 2 is a 35-year-old woman who has had anaphylactic shock three times: in June 2015, 2016, and 2017 and associates these episodes with the consumption of dumplings with a caramel, bun, and the last episode took place during physical exertion few hours after eating waffle. Patient 3 is a 26-year-old man with one-time loss of consciousness after eating mixed nuts and drinking beer. CRD offers the possibility to conduct a detailed diagnostic evaluation of patients with a history of anaphylactic reaction.

[Diagnosis of food allergy]

Food allergy is most often linked to the type I allergic reaction, while IgE-dependent mechanism causes symptoms in only about 50% of patients. If symptoms are coming from other types of allergic reactions we do not have enough standardized diagnostic methods. The purpose of our review is to discuss the possibilities of diagnosis of food allergies. Regardless of the causal mechanism the interview has the most important role in the diagnosis, and the gold standard is a double blind placebo controlled food challenge. Additional tests that can be performed in suspected IgE-mediated reactions include: skin prick tests, specific IgE measurement, component-resolved diagnostics and in doubtful cases basophil activation test (BAT). Due to the fact that the spectrum of the symptoms of the type I food hypersensitivity can include potentially life-threatening reactions, diagnosis is often limited to in vitro assays. In these cases BAT may play an important role--in a recent publication, for the first time BAT reactivity reflected the allergy severity and BAT sensitivity reflected the threshold of response to allergen in an oral food challenge. Atopy patch tests are valuable diagnostic tool in suspected type IV food hypersensitivity, but due to the lack of standardization they are not used routinely. The cytotoxic test has been developed on the basis of the observations that leucopenia developing in the type II hypersensitivity reaction mechanism may be one of the symptoms of food allergy. Unfortunately its use is not justified in any method fulfill the criteria of controlled clinical trial. Food allergy can also develop in the type III hypersensitivity reaction, but there is lack of research supporting the role of IgG measurement in the detection of allergens responsible for symptoms. Each result of additional diagnostic tests before the introduction of food elimination should be confirmed in double-blind, placebo-controlled or open food challenge, because non proper diet is not only ineffective but also can be harmful.