Hyposensitization therapy reduced exhaled nitric oxide in asthmatic children with corticosteroid dependency.

Measurement of exhaled nitric oxide (FeNO) is a simple and noninvasive method for assessment of airway inflammation severity in asthmatic patients. The aim of this study was to investigate whether hyposensitization with extracts of Dermatophagoides pteronyssinus (Der p) and Dermatophagoides farinae (Der f) could decrease airway inflammation as determined by FeNO levels. Ten asthmatic children with corticosteroid dependency were recruited for the study. Eight subjects completed a ten months mite hyposensitization regimen. FeNO concentrations, asthma symptom scores and peak expiratory flow rates (PEFR) were measured monthly before and after treatment. FeNO levels from asthmatic patients were found to be higher before treatment (65.34+/-31.63 ppb). FeNO levels fell significantly after four months' treatment (39.89+/-21.13 ppb; p<0.05). PEFR increased significantly five months after hyposensitization treatment (214.38+/-49.38 vs 251.25+/-28.00; p<0.05). Asthma symptom scores decreased 5 months after hyposensitization treatment (6.84+/-1.22 vs 5.80+/-0.67, p<0.05). Hyposensitization with extracts of Der p and Der f appears to improve clinical symptoms and reduce airway inflammation as determined by FeNO concentrations in children with mite allergy asthma.