Investigation of the Factors Related to Pulmonary Function Decline among Patients with Severe Respiratory Allergy to Mites in Gorgan, Iran

Allergen exposure and sensitivity, asthma progression, and increased airway hyperresponsiveness (AHR) are interconnected. The relationship between mite sensitivity and lung function is still unclear. Therefore, this study aimed to investigate the relationship between mite allergy and   pulmonary function decline in patients with asthma referred to Deziani Allergy Clinic in 2017.

This descriptive cross-sectional study was performed on patients referred to Deziani Allergy Clinic in Gorgan in 2017. The patients were included in the study based on the clinical criteria for asthma. Mite antigen skin test was performed for all patients, and they were divided into two groups: sensitive and non-sensitive. A pulmonologist, allergist, and clinical immunologist performed a pulmonary function test (PFT) and bronchial stimulation test to confirm and evaluate the severity of asthma. Pulmonary function data were statistically compared between the two groups.

In total, 382 patients with a mean age of 42.75±16.50, including 146 (38.2%) males and 236 (61.8%) females, were included in the study. Moreover, 144 (37.7%), 101 (26.4%), and 137 (35.9%) patients had mild, moderate, and severe asthma, respectively. In addition, 173 (45.3%) cases were sensitive to mites. The FVC, FEV1, and FEF 25-75 values were significantly lower in patients with sensitivity, compared to the group without mite sensitivity (P<0.05). PFT results in females sensitive to mites were significantly lower in all cases, except for FEV1/FVC (P<0.050). The use of bronchodilators was significantly associated with improved pulmonary function in those who were over the age of 45 years (P=0.05).

Patients with mite allergy have poorer pulmonary function, and it plays an obvious role in the severity of asthma symptoms. Pulmonary specialists can help better control and reduce these patients' symptoms by adopting appropriate treatment programs, including improving the living environment and presenting the necessary guidelines to reduce contact with this allergen.