Exhaled breath temperature in astmatic children

Asthma is characterized by chronic inflammation of airways. Currently, no traditional method allows an easy daily evaluation of the degree of airway inflammation. Measuring inflammatory biomarkers in the breath is a very attractive approach to monitor asthma inflammation. In recent years, the measurement of exhaled breath temperature (EBT) has been proposed as a method capable of detecting the inflammatory status of the airways. The objective of this study is to strengthen the role of EBT in the diagnosis and monitoring of asthma. The study sample was represented by a group of 40 patients, of both sexes, aged 6-15 years. The elective criteria for submitting patients to EBT determination were abstaining from drugs in the preceding 24 h, fasting for at least 2 h, physical resting for at least 30 minutes, a body temperature between 35-37°C. The temperature in the room of the surveys ranged from 18 to 25°C. The EBT values of asthmatic patients were higher [(median (IQR): 29.77°C (30.67°C to 29.38°C) range 28.46°C min-max 34.78°C] than those of non-asthmatic ones (median (IQR): 28.22°C (29.09°C-27.7°C), range 27.09°C min-max 30.07°C] and this difference was highly significant (p <0.001). Furthermore, no significant difference was found between the EBT values of the following groups of patients: those exposed and not exposed to passive smoking, those receiving and not receiving leukotriene drugs, those receiving and not receiving specific immunotherapy, monoallergic patients and poliallergic ones, those sensitized and not sensitized to house dust, perennial allergic patients and seasonal allergic ones. In addition, the evaluation of the correlation of EBT values with body temperature (r = 0.119, p = 0.464) and ambient temperature (r = -0304, p = 0.057) did not show any significant correlation. Finally, no statistically significant correlation was demonstrated between EBT values and FEV1 (r = -0055, p = 0.81, Fig. 4). In conclusion, the data of the present study further support the hypothesis that EBT can be considered a good method for monitoring asthma