Abstract
<jats:p>Non-erythematous forms of systemic tick-borne borreliosis, or Lyme disease (LD), are considered one of the most difficult to diagnose due to the lack of a pathognomonic (specific) marker of the disease — erythema migrans. In such a situation, the clinician should take into account the season, the patient’s residence or stay in a region endemic for LD, the possibility of an alimentary route of infection with Borrelia when consuming dairy products from sick domestic animals. The non-erythematous form of LD often proceeds as a common acute respiratory viral infection or flu and begins with the appearance of fever, weakness, headache, pain in muscles and joints. Sometimes the disease is masked as other pathologies: myocarditis, chorioretinitis, neurological disorders (facial nerve palsy, radiculopathy, meningoencephalitis), hepatitis. The appearance in a patient in a region endemic for tick activity of any symptoms without erythema migrans requires examination for LD, if these symptoms are not explained by other nosological forms. In order to identify specific antibody titers and assess their dynamics, serological blood testing is prescribed by the enzyme-linked immunosorbent assay, with a repeat after 2–4 weeks. The study of cerebrospinal fluid by polymerase chain reaction for the presence of Borrelia is diagnostically significant in cases of meningoencephalitis. Underestimation of the above-mentioned clinical and anamnestic data and laboratory criteria leads to diagnostic errors, delayed treatment and significantly increases the risk of developing chronic forms of the disease and complications.</jats:p>