Background: Formaldehyde (FA) is well documented as a cause of occupational asthma. Recently, attention has been paid to FA as an allergen and a pollutant that enhances allergic sensitization. We have investigated the prevalence of FA-specific IgE in asthmatic children and the correlation between IgE sensitization to FA and the severity of asthma.
Methods: One hundred and fifty-five children were investigated, 122 of them asthmatic and 33 nonallergic. Specific IgE against FA was measured by CAP RAST. In addition, the patients answered a questionnaire, containing questions on clinical features of their asthma, their living conditions, and symptoms of mucosal irritation.
Results: Of all the subjects assessed, FA-specific IgE was detected in only two asthmatics, and their IgE levels of FA were low (0.42 and 0.46 UA/ml). One of the two patients with FA-specific IgE had severe asthma and frequent symptoms of mucosal irritation, but the other had mild asthma and only rare symptoms of mucosal irritation.
Conclusions: The prevalence of IgE sensitization to FA appears very low in Japanese children, whether or not they have asthma. Therefore, it appears likely that FA is not one of the major allergens causing childhood asthma.