The Role of Spirometry in the Diagnosis of Cough Variant Asthma in Children Aged 5 to 15 Years

Background Cough variant Asthma (CVA) is defined as chronic cough without wheezing, and may be precursor of typical asthma. Thus, the diagnosis of CVA and early intervention can partly inhibit asthma progression.This study aimed to evaluate the role of spirometry in diagniosis of Cough variant Asthma in Iranian Children. Materials and Methods This descriptive observational study included a total of 73 patients, who were referred to the specialized lung clinic of Tabriz Pediatric Center, Tabriz city, Iran. Patients were divided into two groups with classic asthma (n=37) and cough variant asthma (n=36) and basic spirometry parameters such as FEV1, FVC, FEV1/FVC, FEF 25-75% and PEF were measured, and the spirometry findings of each individual were measured based on the European Respiratory Society (ERS) criteria. Results The mean of FEV1 and FVC in the classic asthma group were 83.45 ± 20.49% and 86.45 ± 21.57%, respectively; and in the cough variant asthma group were 87.44 ± 13.99% and 86.8 ± 14.71%, respectively. There was no significant difference between the two groups for the basic spirometry parameters of FEV1 and FVC (p=0.343, P=0.916; respectively). The average FEV1/FVC parameter in the cough variant asthma group was 89.44±13.07, but it was 72.35±8.47 in the classic asthma group, with a significant difference between the two groups (p<0.05). Conclusion There was a significant difference in the FEV1 / FVC value between two groups of cough and classic asthma. Spirometry of patients with cough variant asthma showed the FEF values (25 -75%) were lower than expected; we suggest using spirometry in the diagnosis of cough variant asthma considering small airways changes.