Variation in total and specific IgE: effects of ethnicity and socioeconomic status.

BACKGROUND: Asthma is common in minority and disadvantaged populations, whereas atopic disorders other than asthma appear to be less prevalent. It is unclear whether the same holds true for objective markers of sensitization.
OBJECTIVE: To determine the association of asthma, atopic disorders, and specific sensitization with race and socioeconomic factors.
METHODS: We analyzed total and specific IgE among 882 women (577 white, 169 black, and 136 Hispanic) who delivered a child at a large tertiary hospital in Boston, Mass, and who were screened for participation in a family and birth cohort study. Race/ethnicity and other characteristics were obtained from screening questionnaires. Addresses were geocoded, and 3 census-based geographic area socioeconomic variables were derived from block group information from the 1990 US Census.
RESULTS: Black and Hispanic women were more likely to come from areas with low socioeconomic indicators and were more likely to have asthma than white women. However, these women were less likely to have hay fever and eczema than their white counterparts. Compared with white women, black women had higher mean total IgE levels; had greater proportions of sensitization to indoor, outdoor, and fungal allergens; and were more than twice as likely to be sensitized to > or =3 aeroallergens.
CONCLUSION: The racial/ethnic disparities in atopic disorders may represent either underdiagnosis or underreporting and suggest that allergy testing may be underused in some populations. Differences in total IgE levels and specific allergen sensitization are likely a result of the complex interplay between exposures associated with socioeconomic disadvantage.