Evaluating the Factors that Relate to Asthma Severity in Adolescents

Abstract

Over the past 5 years, we have been engaged in a cross-sectional evaluation of risk factors for higher asthma severity in adolescents aged 13–18. All recruitment takes place through public and private schools. The sample from which our current findings are derived includes 151 adolescents covering a wide spectrum of asthma severity and socioeconomic status (SES) and representing both African American and Caucasians. An asthma severity instrument has been developed and validated for the purpose of this study. This yields an asthma severity score which is a continuous variable. Female gender and the number of positive skin tests are the best independent correlates to the asthma severity score. Among the 18 aeroallergens used in the study, the American cockroach Periplaneta americana is the only one that relates to the asthma severity score in a stepwise regression model. The two other cockroaches, German and oriental, as well as the dust mites Dermatophagoídes farinae and Dermatophagoides pteronyssinus, correlate with the asthma severity only in simple regression analysis. The relationship between asthma severity and cockroach sensitivity is strongest within the lowest-income per family member quartile. This is consistent with the additional observations that (1) significantly higher rates of sensitization for cockroaches are observed in the lowest-income quartile subjects and (2) higher levels of the cockroach allergen Bla g 1 are found in their homes. Preliminary analysis suggests that ethnic background may interact with environmental exposure in that, within the lowest-income quartile, Caucasians have lower sensitization rates to cockroaches and other allergens compared to African Americans. Within the Caucasian population, income does not appear to influence sensitization rates. The treatment that adolescents with asthma receive for their respiratory disease is characterized by an overall low rate of prescribed inhaled corticosteroids (37% in the moderately severe and severe groups). This inadequacy in treatment is accentuated by SES: 28% of adolescents in the highest and 6% in the lowest-income quartile are prescribed these medications. Our findings are consistent with the hypothesis that the higher asthma morbidity and mortality observed in the African American population is related to higher exposure and sensitization to allergens such as those from cockroaches that are more prevalent in lower SES environments. It is possible that genetic factors contribute to the higher degree of sensitization. In addition, individuals of low SES are subjected to inadequate medical management of their asthma.

Race, Ethnicity and Social Class and the Complex Etiologies of Asthma

“…Togias et al demonstrated that socioeconomic status influences allergy in African Americans: African Americans in the lowest income quartile had higher rates of cockroach sensitization than African Americans in higher income brackets. In contrast, there was no association between cockroach sensitization and income level among European Americans [72]. In addition, our group recently demonstrated that ancestry interacts with SES to modify the risk of asthma [2].…”

E- and P-Selectins Are Essential for the Development of Cockroach Allergen-Induced Airway Responses

“…In humans, CRA may be particularly important in the growth of severe bronchial asthma among inner-city children (18,28,29). In susceptible humans and animal species, allergens induce Th2-driven production of allergen-specific IgE, airway hyperreactivity, peribronchial inflammation, and direct epithelial cell damage (2,3,30,31).…”

Effect of indoor air pollution from biomass combustion on prevalence of asthma in the elderly.

“…Exposure to several specific air pollutants, such as respirable particulate matter [≤ 10 µm in aerodynamic diameter (PM 10 )], carbon monoxide (CO), ozone (O 3 ), sulfur dioxide (SO 2 ), and nitrogen dioxide (NO 2 ), has been associated with increased asthma symptoms (Baldi et al 1999;Bates 1995;Castellsague et al 1995;de Diego Damia et al 1999;Greer et al 1993;Hajat et al 1999;Koren 1995;Zhang et al 1999). In indoor environments, home bioallergens such as dust mites, molds, cockroach parts, and animal dander (Dales et al 1991; Lewis et al 2002;Litonjua et al 1997;Rosenstreich et al 1997; Thorn et al 2001;Togias et al 1997;Weiss et al 1993), and household cleaning agents, pesticides, and mosquito coil smoke (Azizi and Henry 1991;Azizi et al 1995;Weiss et al 1993) have been linked to increased risk of developing asthma. A number of lifestylerelated factors, such as outdoor activity and exercise, have also been associated with modifying asthma (Platts-Mills and Woodfolk 1997).…”