The aim of this study is to investigate the role of cytokines (TNF-α, IL-6, IL-10, and PAF), cortisol, and IgE in the pathogenesis of croup and the factors determining its clinical severity. Patients diagnosed with croup at the Pediatric Emergency Department were included and thirty healthy children were included as a control group. Patients` demographic characteristics, clinical findings, recurrent croup history, and patient-family atopy history were recorded. Patients were grouped according to the Westley croup scoring system. Blood samples were taken from the control group and the patients for cytokines and cortisol. Respiratory pathogens were studied with PCR. Sixty-nine pediatric cases who were diagnosed as croup were included in the study (34 mild, 31 moderate, 4 severe). Group comparisons were made in terms of mild and moderate/severe groups. In the moderate/severe group, IL-10 and cortisol levels were higher than the mild group. The moderate/severe cortisol levels between 12:00 am-6:00 pm were found to be higher. PAF and TNF-alpha levels were detected to be higher in patients with a history of atopy. Viral agents were isolated in 45 patients; rhinovirus PCR tests were positive in 22 patients. In this study, rhinovirus was the most common etiology for croup. Increased levels of IL-10 and cortisol in the moderate/severe group indicate that different systemic and local mechanisms may play a role in the pathogenesis of croup.

Keywords: children, cortisol, croup, cytokines