Background and Objectives: The COVID-19 pandemic has led to significant changes globally, which has also affected patients with type 1 diabetes mellitus (T1DM). This study aimed to determine the incidence of T1DM and the characteristics of diabetic ketoacidosis (DKA) during the pandemic comparing it to pre-pandemic period. Materials and Methods: Data from patients <19 years with newly diagnosed T1DM between 1st January 2017 and 31st December 2021 from four regional centers in Vojvodina were retrospectively collected and analyzed. Results: In 2021, the highest incidence of T1DM in the last five years was recorded, 17.3/100,000. During the pandemic period (2020–2021), there were 99 new-onset T1DM, of which 42.4% presented in DKA, which is significantly higher than in the pre-pandemic period (34.1%). During the pandemic, symptom duration of T1DM lasted significantly longer than before the COVID-19 period. At the age of 10–14 years, the highest incidence of T1DM and COVID-19, the highest frequency rate of DKA, and severe DKA were observed. Conclusions: The pandemic is associated with a high incidence rate of T1DM, longer duration of symptoms of T1DM, a high frequency of DKA, and a severe DKA at diagnosis. Patients aged 10–14 years are a risk group for the occurrence of T1DM with severe clinical presentation. Additional studies are needed with a longer study period and in a wider geographical area, with data on exposure to COVID-19 infection, the permanence of new-onset T1DM, and the psychosocial impact of the pandemic.

Tick-borne encephalitis (TBE) is a vaccine-preventable viral infection that poses significant public health challenges, particularly in regions where tick-borne diseases are endemic. This case report describes a 2-year-old boy with confirmed abortive TBEV infection following a tick bite during travel to Switzerland. The patient developed fever and mild symptoms but did not exhibit central nervous system involvement. The case underscores the importance of raising awareness among healthcare providers and travelers from non-endemic areas, such as Serbia, about TBE risk and the potential benefits of preventive vaccination. Strategic immunization campaigns could mitigate the public health impact of travel-related TBE.

Background/Objectives: To investigate if the severity and presentation of multisystem inflammatory syndrome in children (MIS-C) vary between different severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants. Methods: This retrospective study included 59 patients aged 0–18 years, diagnosed with COVID-19 and MIS-C, treated and monitored over a one-year period after discharge from hospital. The patients were grouped according to the predominant SARS-CoV-2 variant. The predominant variant of SARS-CoV-2 was assumed by the date of hospitalization. The following patient data were collected: demographic data (age, sex), information on comorbidities, body mass index, clinical data (fever and duration of febrile periods, symptoms of Kawasaki-like phenotypes, and presence of respiratory, cardiovascular, gastrointestinal, neurological and other symptoms), and laboratory and imaging findings. Results: In total, 24 (41%), 19 (32%), and 15 (25%) patients were diagnosed with MIS-C during the Alpha, Delta, and Omicron periods, respectively (63.8% were males; 36.2% were females). Comorbidities were present in 49% of patients. Respiratory symptoms were the most common during the Delta period (73%, p = 0.028). There was no statistically significant difference in the occurrence of other symptoms, laboratory findings, treatment, complications, and long-term outcomes between groups. Conclusions: No significant correlation was found between hospitalization date (used to estimate COVID-19 variant) and presentation/severity of MIS-C.

Ataxia-telangiectasia is a rare autosomal recessive disorder that is difficult to diagnose due to its unpredictable presentation. It is characterized by cerebellar degeneration, telangiectasias, immunodeficiency, frequent pulmonary infections, and tumors. Immune system abnormalities manifest as disruptions in both cellular and humoral immunity. The most common findings include decreased levels of immunoglobulin classes (IgA, IgM, IgG, and IgG subclasses) and a reduced number of T and B lymphocytes. A four-year-old girl was initially evaluated and treated for skin lesions that presented as crusts spreading across her body. She was monitored by a pulmonologist due to frequent bronchial obstructions. Over time, she developed bilateral scleral telangiectasia, saccadic eye movements, and impaired convergence. Her gait was wide-based and unstable, with truncal ataxia and a positive Romberg sign. Laboratory tests revealed decreased immunoglobulin G levels, subclass IgG4 levels, elevated alpha-fetoprotein, and a reduced number of T and B lymphocytes. Brain magnetic resonance imaging showed cerebellar atrophy. Whole-exome sequencing identified heterozygous variants c.1564-165del, p.(Glu5221lefsTer43), and c.7630-2A>C in the serine/threonine-protein kinase ATM (ataxia-telangiectasia mutated) gene, confirming the diagnosis of ataxia-telangiectasia. Following diagnosis, treatment with intravenous immunoglobulin replacement was initiated along with infection prevention and management. The goal of this case report is to raise awareness of the atypical initial presentation that may lead to a diagnostic delay. We emphasize the importance of considering ataxia-telangiectasia in the differential diagnosis, even when classical neurological signs are not yet evident.

Background and Objectives: The aim of this study was to identify clinical features and laboratory findings that correlate with and predict pathological echocardiographic findings in children diagnosed with Multisystem Inflammatory Syndrome. Materials and Methods: Retrospective study included all patients aged 0–18 diagnosed with Multisystem Inflammatory Syndrome and hospitalized at our clinic from July 2020 to December 2022. The clinical and laboratory data of 61 patients were studied and compared between two subgroups (normal/abnormal echocardiography). Results: Elevated values of high-sensitivity troponin I were observed in 65.57% patients with MIS-C. The mean high-sensitivity troponin I value in the whole sample was 400.89 ± 1989.31 pg/mL. In patients with pathological echocardiographic findings, the mean value was 1240.24 ± 3609 pg/mL, while in patients with normal echocardiographic findings, it was 52.87 ± 71.86 pg/mL. Even though mean value was higher in the group of patients with abnormal echocardiography, no statistically significant difference was observed between high-sensitivity troponin I values in patients with and without pathological echocardiographic findings. Troponin levels were not in good correlation with pathological echocardiographic findings (point-biserial correlation; rpb = 0.25, p = 0.054) and were not good predictors of pathological echocardiographic findings (logistic regression; Chi² = 3.77, p = 0.052). Logistic regression showed significant positive correlation of blood urea nitrogen levels and the degree of fever with abnormal echocardiographic findings (Chi² = 10.04, p 0.002/Chi² = 6.10, p = 0.013, respectively). Conclusions: Only blood urea nitrogen levels and high fever showed statistically significant correlation and predictive value for abnormal echocardiographic findings in children with Multisystem Inflammatory Syndrome. High sensitive troponin I had no significant power to discriminate between normal and abnormal echocardiographic findings.

The gut microbiota plays an important role in immune homeostasis, allergic disease pathogenesis, and drug metabolism, potentially influencing therapeutic efficacy and safety. Conversely, pharmacotherapy may modify gut microbial composition and function, creating bidirectional host–drug–microbiome interactions that remain incompletely understood. This narrative review summarises current evidence on interactions between the microbiome and therapies for allergic diseases, focusing on antihistamines, corticosteroids, leukotriene receptor antagonists, and biologic agents. Evidence is evaluated from two complementary perspectives: an exposure axis, relevant mainly to orally administered drugs, and a response axis, particularly applicable to biologic therapies. Direct microbial biotransformation has been demonstrated most convincingly for glucocorticoids, with the organosteroid reductase ABC (OsrABC) pathway of Clostridium steroidoreducens reducing systemic prednisolone exposure in a gnotobiotic model. For H₁-antihistamines and leukotriene receptor antagonists, evidence remains limited and inconsistent. The microbiota may also indirectly influence treatment outcomes through effects on epithelial barrier integrity, microbial metabolite production, and immune regulation. Although anti-allergic therapies can alter gut, airway, and skin microbial communities, no validated microbiome signature currently predicts treatment efficacy or safety. Future prospective studies integrating microbiome, metabolome, pharmacokinetic, pharmacodynamic, and clinical data are needed to establish reliable biomarkers and support personalised pharmacotherapy for allergic diseases.