Association of allergic diseases with fever and frequent respiratory infections in children

Abstract

Currently, allergies have already become the most common chronic disorders. Inflammation is the first and main mechanism of the body's defense against foreign agents. The absence of a febrile reaction to respiratory infections may indicate qualitative changes in the immune response. We hypothesized that the prevalence of allergic patients in economically developed countries is also related to availability of various medical drugs for treating fever. To investigate the relationship between the development of allergic diseases (ADs), frequency of respiratory infections, and the nature of their febrile responses, a two-stage study was conducted. At the first stage, we have examined a cohort of 505 randomly selected children aged 1, 2, 3, 4, 5, 6, and 7 years. Only 59.0% of them were found to be free of ADs, which is comparable to the findings of a study conducted on over 9,000 children by Belgrave D.C. et al. in 2014. In the group with allergies, the number of children with frequent respiratory infections was significantly higher, and the peak incidence of allergy and frequent infections was observed at the ages of 3 and 5. It was found that a significant portion of children (46.4% among those with allergies, compared to 27.4% in the group without allergies) never experienced high fever ( 38.5 °C), and 26.1% of respondents stopped experiencing fevers a year before developing allergies. Since recurrent respiratory infections in children are more often associated with development of bronchial asthma (BA), we studied the nature of acute diseases in 60 children with BA in dynamics. Significant differences were found in the degree, duration of fever, and course of the disease, depending on the duration of BA. The degree of fever is higher in children before the development of asthma, but decreases after the formation of chronic inflammation and making the diagnosis, and becomes even lower at later terms. A lower degree of temperature response is associated with an increased duration of colds and fever. This body temperature does not reach febrile levels and is not sufficient to fight infections, but rather acts as a "thermostat" for microorganisms. We consider the data obtained to be a change in immune reactivity in children with ADs, which is one of the reasons for incomplete acute inflammation in response to infections, thus contributing to the development of latent sensitization and transition to a qualitatively different level of response with the formation of a persistent chronic inflammatory process. These findings provides a reason for avoiding phobias against febrile reactions when treating acute inflammatory conditions.