Abstract

Background: Lyme borreliosis/European borreliosis (LB/EB) is a multisystemic infection caused by the bacterium Borrelia burgdorferi, which is transmitted to humans by the bite of ticks and other hematophagous insects. Transmitted borrelia can occupy any organ where it causes a silent inflammation, which in sensitive persons is intermittently repeated chronically. Objective: The aim of this paper was to determine how much Borrelia burgdorferii participates in the occurrence of chronic urticaria in children and adults Methods: In the 13-year period from January 1, 2013 to December 31, 2025, a study of all manifestations of Lyme borreliosis was conducted on a sample of 1,059 patients, treated and monitored in the Private practice of an infectious disease specialist. The research was retrospective-prospective, descriptive, clinical and analytical. It was carried out in three phases: the first retrospective phase and the second two prospective phases. The diagnosis of LB was established on the basis of anamnestic-epidemiological data, clinical picture, clinical findings of new borreliosis markers and performed examinations. Serological confirmation of borreliosis was done using ELISA, WB and Immunoblot methods, as well as the ex-yuvantibus method, and in the last six months of 2025, additionally, the finding of bacteria Borreliosis in a dark field with a light microscope. Results: The results showed that 92.1% of the patients in the study group had intermittent migratory redness with itching. In the majority of patients, redness was without exudation or with little or no exudation. In 4.8% of patients, typical urticarial changes were found that occurred occasionally or daily. In all subjects, we serologically confirmed the presence of Borrelia burgdorferi. All patients had intermittent itching of the skin, which lasted for years. Conclusion: Based on the results, it can be concluded that Borrelia burgdorfrii is one of the most important factors in the development of chronic urticaria in monitored patients with 96.9%. Due to its persistence in the macroorganism, it causes reduced tolerance to food. Only 3.1% of cases of urticaria are caused by some other factors. In all cases of chronic urticaria, new clinical markers should be sought on the patients’ skin. Serologically look for antibodies to Borrelia protein sequences in an immunoblot. In the active phase, look for Borrelia with a light microscope in the dark field. Administer antibiotic therapy together with antihistamines. Exclude food to which the intolerance test confirmed hypersensitivity greater than „2“.

Key words: Lyme disease/European borreliosis, Borrelia burgdorferi, chronic urticaria.