Clinical and laboratory comparison of Covid-19 and influenza A/B in children

Background: The clinical picture of COVID-19 shows significant similarity with influenza. In this study, it was aimed to compare the clinical and laboratory findings between pediatric patients diagnosed with COVID-19 and those with influenza A or B, and to obtain data on the differential diagnosis of COVID-19 from influenza in children. Methods: The study included 104 patients with COVID-19, 140 patients with influenza A and 135 patients with influenza B (379 patients in total) who were admitted to our tertiary hospital with symptoms of acute respiratory tract infection. Results: Fever, cough, runny nose, and pharyngeal hyperemia rates were significantly lower in patients with COVID-19 than in those with influenza A/B. The highest leukocytosis and lymphocytosis rates were seen in influenza A patients. Eosinophil levels were found significantly lower in the influenza A/B patients compared to the COVID-19 group. C-reactive protein levels were significantly higher in the influenza A/B group when compared with the COVID-19 group. The mean PDW value was significantly higher in the COVID-19 patients compared to influenza A/B. Conclusions: Our study data show that low body temperature and loss of taste and smell support the diagnosis of COVID-19, and fever, cough, pharyngeal hyperemia, and runny nose support the diagnosis of influenza. While leukocytosis and increased C-reactive protein suggest influenza, high PDW and eosinophil levels support COVID-19.