A study of Spirometric parameters in non asthmatic allergic rhinitis

Allergic rhinitis (AR) is a common IgE -mediated inflammatory condition characterised by sneezing, nasal congestion, itching and rhinorrhoea. Nasal allergy is a strong risk factor for the onset of asthma in adults. Bronchial hyper-responsiveness (BHR) is a distinct feature of pathophysiology in asthma. Spirometric parameters like Forced Expiratory Volume in first second [FEV1] and Forced Expiratory Flow [FEF _25-75%] are known to be impaired in patients with allergic rhinitis. We studied these parameters in subjects of AR who have never experienced any chest symptoms. It is well known that, subjects with allergic rhinitis are at greater risk of developing overt bronchial asthma in future.

All patients presented with symptoms of allergic rhinitis without history of bronchial asthma were included. Patients those who were clinically diagnosed with allergic rhinitis were evaluated with absolute eosinophilic count, serum IgE and Spirometric assessment. In spirometry, post bronchodilator FEV1 reversibility and post bronchodilator FEF _25-75% values were used to assess lower airway abnormalities.

Among 61 subjects, 32 were males and 29 were females. The maximum numbers [28] of patients were in 21-35 age group. Absolute eosinophil count was elevated in 38% of patients. 33% of patients showed elevated IgE values above 1000. 43% of patients showed FEV1 reversibility which is a sign of Bronchial hyperreactivity. 5% of patients showed impaired post bronchodilator FEF _25-75% which indicates presence of small airway disease. There was significant correlation between FEV1 reversibility and elevated IgE.

Impaired spirometric parameters indicate coexistence of bronchial impairment and hence predisposition to progression from allergic rhinitis alone to overt asthma in future. Thus careful evaluation of lower airway has to be done to rule out coexisting subclinical asthma.