Tobacco hypersensitivity and environmental tobacco smoke exposure in a pediatric population

Background: Skin testing and RAST have verified the existence of tobacco-sp ecific IgE. However, published studies report conflicting results concernin g the clinical significance of tobacco IgE. Previous studies have not focus ed on the role of environmental tobacco smoke (ETS) as it relates to tobacc o hypersensitivity (TH) in nonsmoking children. Objective: We used nonsmoking pediatric patients to investigate the relatio nship between ETS and TH. Methods: Children, ages 4 to 10 years, were prospectively enrolled. ETS exp osure and smoke-triggered symptoms were recorded by questionnaire and physi cian history. Patients were given a skin test (ST) with a panel of aeroalle rgens plus tobacco extract. A ST reaction to at least one aeroallergen clas sified a patient as atopic; a ST reaction to tobacco classified a patient a s TH. Results: We enrolled 170 patients, mean age 7.2 years. We found 58 (34%) pa tients reported routine exposure to ETS and 78 (46%) patients reported ETS- induced symptoms. We found 121 (71%) atopic patients and 61 (36%) TH patien ts. TH was more common in atopic patients (r < .0001) and those routinely e xposed to ETS (P < .05). However, TH failed to predict ETS-induced symptoms in either atopic or non-atopic patients (PPV = 0.40, NPV = 0.69). Conclusions: We evaluated the clinical significance of TH in a nonsmoking p atient population related to ETS exposure, We concluded that although TH is statistically related to atopy and ETS exposure, the low predictive values of skin testing fur TH limit its clinical usefulness.