Background: Some studies suggest that the prevalence of sensitization to cockroach allergens may be higher in the United States than in Europe, but there are no comparable data from population-based studies.
Objectives: To determine the prevalence of allergic sensitization to German cockroach (GCR) in German schoolchildren and to assess its clinical relevance; and to determine the exposure to the major GCR allergen Bla g 2 in non-selected homes and nurseries.
Methods: The prevalence of allergic sensitization to GCR and other allergens was determined by measurement of specific IgE and skin-prick tests in a cross-sectional study of 2993 children aged 5-11 years in Dresden, Germany. The prevalence of atopic disease was determined by questionnaire, and pulmonary function and bronchial hyperresponsiveness to hypertonic saline were measured. Bla g 2 exposure was determined on floors of 187 kitchens and 47 nurseries by a commercial sandwich ELISA.
Results: One hundred and twenty-seven (4.2%) of the children had specific IgE (> 0.7 kU/L) against GCR. Among children with current wheeze, 8.4% were GCR-sensitized. Compared to data from the United States, the prevalence of sensitization to cockroach was similar in children without asthma (3.9%), but less frequent in asthmatic children from Dresden (6.1%). After adjustment for positive reactions to other allergens (SX1 test) no significant impact of GCR sensitization on wheeze or other symptoms and diagnoses was found. Bla g 2 was detected in 29% of the kitchens and 43% of the nurseries. None of these sites had exposure levels above the proposed threshold for causing disease of 80 ng/g dust.
Conclusion: The data suggest that allergic sensitization to GCR is less frequent in asthmatics from Dresden, Germany than in US cities. The data indicate that GCR sensitization is not an independent risk factor for asthma and other atopic diseases in 5-11-year-olds from this city.