Sugawara H, et al. - Researchers determined the link between cough variant asthma (CVA) and impulse oscillometry system (IOS), as well as the variability in the curative impacts of inhaled corticosteroids (ICSs) among the subtype classifications by IOS. Assessments included ICSs randomly prescribed in daily medical care such as coarse-particle ICS (fluticasone propionate [FP]), fine-particle ICS (mometasone furoate [MF]), and moderate-particle ICS (budesonide [BUD]). The Leicester cough questionnaire (LCQ) was used to determine therapeutic impacts. Based on IOS measurements, three separated subtypes were recognized: central, peripheral, and resistless. In the central type, a remarkably lower LCQ was seen in the MF group vs FP and BUD. A significantly lower LCQ was seen in the peripheral type in the FP group, compared to that in MF and BUD groups. The MF group vs BUD showed significantly lower LCQ in the resistless type. By 4 weeks of ICS use, improved IOS factors were observed. Overall, as far as the therapeutic effectiveness of ICSs in CVA was concerned, they observed a robust link between IOS subtype classification and ICS particle size. The ICS particle size appeared significant to be determined, based on the IOS subtype classification, prior to treatment.