Seasonal outbreaks of respiratory syncytial virus are common among young children and represent an important clinical problem. The infection can affect all floors of the respiratory system. Respiratory syncytial virus is highly infectious and is the most common aetiological agent of bronchiolitis. It is estimated that 90% of children develop respiratory syncytial virus infection by the age of 2 years. In Poland and other countries of the northern hemisphere, these infections usually occur between October and May, with a peak in January–February. During the global COVID-19 pandemic, a significant change was observed in the epidemiology of respiratory syncytial virus infections in Europe and worldwide. The massive use of nonpharmacological interventions, such as closing nurseries, kindergartens, limited interpersonal contact, social distancing, strict hygiene rules and the use of protective masks, resulted in the absence or episodic occurrence of many seasonal infections, including those of respiratory syncytial virus aetiology, in 2020. In 2021, a so-called compensatory epidemic of syncytial virus aetiology was observed, i.e. a significant increase in the incidence associated with the extinction of collective immunity and an increasing proportion of susceptible individuals. The aim of the present study was to retrospectively analyse the incidence of respiratory syncytial virus infections in children hospitalised in the Department of Paediatrics, Paediatric Nephrology and Allergology of the Military Institute of Medicine in Warsaw in the years 2020–2021. We also discussed the prevention and treatment of infections, as well as the association of bronchiolitis with the development of asthma in children.

The skin microbiota is a complex ecosystem consisting of bacteria, fungi and viruses. The role of the human skin microbiota is to maintain homeostasis in the body. Disruption of the balance of the natural composition of the human microbiome can lead to the development of inflammation and infection. Atopic dermatitis is a chronic and recurrent non-infectious, inflammatory dermatosis characterised by erythematous and exfoliative skin lesions, accompanied by pruritus and a tendency to superinfection. Defect in the epidermal barrier, immune dysfunction and changes in the composition of the skin microbiome underlie the pathogenesis of atopic dermatitis. It has been found that the diversity of atopic skin microbiota is significantly reduced, with a decrease in the number of Cutibacterium, Streptococcus, Acinetobacter, Corynebacterium and Prevotella, and a concomitant increase in the percentage of Staphylococcus bacteria, especially S. aureus. It accounts for about 20% of skin microbiome in healthy people, while in patients with atopic dermatitis the percentage of S. aureus can increase up to 30–100%. In addition, there is a positive correlation between S. aureus skin colonisation and disease severity. S. aureus plays a key role in the development of skin inflammation in the course of atopic dermatitis, including through the induction of lymphocyte expansion, release of cytokines, pro-inflammatory lipoproteins, and stimulation of mast cell degranulation. Therefore, properly selected and regular treatment of atopic dermatitis diversifies the skin microflora, often leading to clinical improvement in the patient.

Background/Objectives: Human breast milk is a biologically active fluid. It contains immune cells, stem cells, epithelial cells, and lactocytes. These components may support infant development and immune defense. While milk composition is known to vary with physiological and nutritional factors, the impact of the home environment remains poorly understood. The aim of this study was to examine how selected conditions affect the cellular composition of breast milk. Methods: We conducted a cross-sectional study involving 49 lactating mothers of healthy infants under 6 months of age. Breast milk samples were analyzed using flow cytometry. We measured proportions of immune cells (CD3⁺, CD4⁺, CD8⁺, CD19⁺, and CD16/56⁺), hematopoietic stem cells (CD34⁺), mesenchymal stem cells (CD105⁺, CD73⁺, and CD44⁺), and lactocytes (CD326⁺ CD73⁺ and CD326⁺ CD73⁻ phenotypes). Participants completed a questionnaire assessing number of children, co-sleeping, pet ownership, and number of household members. Results: Mothers with more than one child showed higher percentages of CD4⁺ (p = 0.047) and CD8⁺ (p = 0.031) T cells and fewer CD73⁺ lactocytes (p = 0.028). Co-sleeping was associated with lower levels of CD3⁺ T cells in milk (p = 0.021). Pet ownership correlated with a lower proportion of cytotoxic CD8⁺ cells (p = 0.048). The number of household members had no significant effect. Conclusions: Domestic factors such as number of children, co-sleeping, and pet exposure are associated with shifts in the immune and lactocyte cell composition of breast milk. These findings suggest that breast milk dynamically adapts to maternal and household-level immune stimuli.

Influenza is an acute viral respiratory disease, which is particularly common in the paediatric population. Every year it affects about 25% of children. According to the National Institute of Public Health – National Institute of Hygiene, almost three times as many cases of influenza were registered in the 2022/2023 infectious season compared to previous years. However, in the era of the influenza epidemic, diagnostic vigilance should be maintained, keeping in mind that the symptoms of some serious bacterial infections may initially mimic those of influenza. We present a case report of a 3-year-old boy with influenza-like symptoms, who was finally diagnosed with lobar pneumonia complicated by parapneumonic effusion. Early diagnosis and treatment spared the patient from invasive treatment for complications of pneumonia.

Renal ectopia and renal fusion belong to a group of congenital anomalies of the kidney and urinary tract that mostly remain asymptomatic and are diagnosed incidentally. Patients with congenital renal anomalies are prone to urinary tract infections and stone formation, and ultimately more likely to develop chronic kidney disease. Pancake kidney is one of the rarest types of renal anomaly, with complete fusion of the superior and inferior poles as well as the middle parts of both kidneys in the pelvic cavity into a pancake-like mass. Imaging studies play a key role in the diagnosis of this anomaly. We present a case of a girl diagnosed with pancake kidney at the age of 8 years. The patient did not present with any alarming symptoms and the suspicion of renal malformation was raised after an abdominal ultrasound, which shew that the left kidney was missing from its typical location. Ultimately, computed tomography allowed for precise imaging of the urinary tract and establishing the diagnosis.