Background: Atopic sensitization is a well-known risk factor for asthma and bronchial hyperresponsivness. IgE-mediated responses contribute to allergy and asthma. Blood eosinophilis are known to be an indirect marker of airway inflammation in asthma.
Objective: To evaluate the interrelationship between skin prick test, serum total & specific IgE levels, eosinophilia and asthma severity in atopic asthmatics.
Methods: One hundried ten atopic asthmatics patients were randomly selected and 30 matched control subjects were included. All were submitted to detailed clinical history and examination , pulmonary function testing ,skin prick testing to 17 common allergens , blood eosinophil counts and both total and specific IgE levels. Asthma severity was assessed according to GINA guidelines.
Results: There was a highly significant relationship between total IgE, eosinophil counts & percent (p<0.0001) from one hand and severity of asthma from the other hand .There was a significant increase in severity of asthma with the increasing number of positive allergens in SPT & also when asthma was associated with other allergic diseases (p<0.04).Increased number of positive allergens was associated significant increase in the level of total IgE, eosinophil count & percent (p<0.0002).Total IgE was significantly higher in atopic asthmatics with eosinophilia than those without (p<0.0001). Eosinophil count & percent, total IgE and specific IgE were significantly higher in patients than controls (p<0.0001). The most common allergens for atopic asthma in our locality were D. pternoyssinus, followed by D.farinae then Cockroach extract.
Conclusions: Atopic asthmatic patients with a higher serum concentration of both total IgE and specific IgE ,blood eosinophilia and sensitivity to more than one allergens in SPT have a higher asthma severity.