Fibromyalgia can be defined as a chronic pain condition, affecting the musculoskeletal system, etiology and pathophysiology of which is sufficiently understudied. Despite the fact that many authors consider this entity to be a manifestation of central sensitization, and not an autoimmune disease, the high prevalence of fibromyalgia in patients with post-COVID-19 conditions requires taking a fresh look at the causes of the disease development. During the patient examination, the authors identified a combination of symptoms that occurs so often, that they can be carefully described as a clinical pattern. These manifestations include young age, female gender, joint hypermobility, the onset of pain after COVID-19, physical traumatization of one particular tendon and the development of the fibromyalgia pain syndrome during the next several weeks. As well as an increase in the titer of antinuclear antibodies and some other systemic inflammation factors. It can be assumed with great caution that local damage to the connective tissue in patients with joint hypermobility, having COVID-19 as a trigger factor can lead to the development of fibromyalgia syndrome. This article presents three clinical cases that illustrated this hypothesis.

Chronic pain may affect 30–50% of the world’s population and an important cause is small fiber neuropathy (SFN). Recent research suggests that autoimmune diseases may be one of the most common causes of small nerve fiber damage. There is low awareness of SFN among patients and clinicians and it is difficult to diagnose as routine electrophysiological methods only detect large fiber abnormalities, and specialized small fiber tests, like skin biopsy and quantitative sensory testing, are not routinely available. Corneal confocal microscopy (CCM) is a rapid, non-invasive, reproducible method for quantifying small nerve fiber degeneration and regeneration, and could be an important tool for diagnosing SFN. This review considers the advantages and disadvantages of CCM and highlights the evolution of this technique from a research tool to a diagnostic test for small fiber damage, which can be a valuable contribution to the study and management of autoimmune disease.

SARS-CoV-2 infection may cause such complications as post-COVID-19 syndrome, which includes chronic fatigue, myalgia, arthralgia, as well as a variety of neurological manifestations, e.g., neuropathy of small fibers, hearing and vestibular dysfunction, and cognitive impairment. This clinical case describes a 41-year-old patient suffering from post-COVID-19 syndrome and chronic fatigue syndrome. A detailed examination was performed, including an in-depth study of peripheral and central hearing and vestibular functions, as well as small nerve fibers length and density in the skin and cornea of the eye. Contrary to expectations, no peripheral nervous system dysfunction was detected, despite the presence of dizziness and gait instability in the patient. Hearing tests (gap detection test and dichotic test) showed central auditory processing disorders. The evaluated lesion in the processing of temporal and verbal auditory information can be a significant factor contributing to additional overload of the neural activity and leading to chronic fatigue when performing daily activities in patients with CFS and post-COVID-19 complications.

In the 21st century, environmental factors of anthropogenic origin began to come under the close attention of scientists. There is an increase in the incidence of various nosological forms, with autoimmune pathogenesis. Among them, one of the most important endocrinopathies is type 1 diabetes mellitus (DM1), especially in children. In parallel, the urban population continues to grow. At the same time, up to 60% of the urban population of Russia (about 58.8 million people) lives in areas with high and very high levels of environmental pollution. Among the pollution factors, special attention is now drawn to the car and road complex, during the operation of which destruction aerosols are formed, forming a mixture of particles that includes a chemical composition of a mixture of silicon oxides, aluminum, iron, calcium, magnesium and organic substances, as well as compounds with heavy metals. The article analyzes the main sources of environmental pollution in Russian Federation, identifies the central/dominant model, and predicts significant and secondary models of possible regional correlation between the factors related to urbanization and spread of an autoimmune disease, which is DM1 among children of Russia.

The paper presents data on relationships between the regional incidence of the autoimmune pathology of the thyroid gland among children in Russia and the contents of some microelements in their hair, namely those known to have an adjuvant effect on the immune system. The results relate to all Federal Districts of Russia in 2008-2017. А regression model of these relationships is proposed. It has been shown that the region-specific contents of iodine and mercury but not aluminium in the hair of children positively correlate with the regional incidence of Graves’ disease. Thus, an increase in the exposure to an essential microelement in excess of need, as well as an increase in the exposure of toxic trace elements, can adversely affect autoimmunity. The data are discussed in comparison with literature on this topic and in the context of predicting and preventing the risk of autoimmune thyroid disease in pediatrics, especially with regard to the optimal choice of vaccines. The issues related to the permissive effect of the various factors that form the mosaic of autoimmunity, on the resulting changes in reactivity are addressed. The bill for obligatory iodization of cooking salt in the Russian Federation is criticized because it does not take into account regional differences in the availability of trace elements.

Objective. To evaluate the autonomic dysfunction of cardiovascular system (CVS) in patients with post-COVID syndrome with the help of active orthotest and heart rate variability methods. Material and methods. 70 patients with PCOS were examined, who were divided into 2 groups. Group 1 patients received standard therapy and Cytoflavin for 35 days, Group 2 patients received only standard therapy. Patients were examined by a neurologist in dynamics, the severity of asthenic syndrome was assessed on the MFI-20 scale, HRV and orthostatic test parameters. Results. When assessing HRV, an increase in the activity of humoral and nervous levels of CVS regulation was observed, which decreased against the background of cytoflavin therapy. Prior to the start of treatment, the activity of the parasympathetic department prevailed in patients, despite a decrease in its reactivity. All patients had a change in parasympathetic regulation, and therefore they were divided into subgroups with excessive and insufficient parasympathetic activity. Against the background of therapy, the elimination of differences between the groups with normalization of the main HRV indicators was observed. The severity of asthenia decreased after the course of treatment (values on the MFI-20 scale, p=0.0498). Conclusion. In patients with PKS, signs of dysautonomia were revealed, the probable cause of which may be autonomic neuropathy with a predominant lesion of the parasympathetic link. The use of Cytoflavin can have a significant positive effect in the complex treatment of such patients.