Clinical-anamnestic analysis of patients diagnosed as "Anaphylaxis" hospitalized in Moscow medical hospitals

Background: Anaphylaxis is a severe hypersensitivity reaction. The incidence of anaphylaxis remains underestimated and there remains a low level of vigilance among all specialties, leading to underdiagnosis and consequent lack of appropriate treatment. This work is the first systematized clinical and epidemiological study performed on a cohort of patients with a history of anaphylactic reactions (AR) over 18 years of age. Aims: study of epidemiologic features of anaphylaxis within one region of the Russian Federation, identification of its most frequent phenotypes and possible cofactors of its development, as well as analysis of the main errors in the management of patients with AR Materials and Methods: The study was conducted based on the retrospective stage analysis of data from medical records of patients with AR of the Unified Medical Information and Analytical System (EMIAS) of Moscow for the period from 2019 to 2022. The final sample comprised a cohort of 241 patients. Results: In the analyzed cohort, females (n=150; 62.2%) were predominant compared to males (n=91; 37.8%).   Medications (n-171 (70.95%) dominated the list of causative agents. The leading clinical phenotype of AR in the analyzed hospitalized cohort was characterized by cardiovascular symptoms (73 (30.3 %%)). The risks of severe course increased with age (older than 44 years) (p=0.006). At the prehospital, epinephrine therapy was given to 128 (69.9) patients out of 183 (75.9 %) patients. There was a correlation between the absence of epinephrine administration at the prehospital and the development of biphasic course of AR in the aftermath, (p0.001). Only 15 (38.5%) patients with anamnesis of anaphylaxis were previously informed about the necessity to carry epinephrine solution. It was shown that COVID-19 significantly contributed to the development of severe forms of AR (p=0.008). Conclusions: Anaphylaxis is a life-threatening pathology requiring emergency medical care, regardless of the severity of the initial symptoms. Variations in the clinical symptoms that constitute the diagnostic criteria for anaphylaxis, differences in algorithms, and limitations of existing coding systems make it difficult to summarize epidemiological data and compare study results. Older age remains a risk factor for the development of severe AnR confirmed in our cohort.