People with atopy are genetically predisposed to produce IgE antibodies in response to common household allergens and have at least one atopic disease (i.e., asthma, allergic rhinitis, or atopic eczema) (Kay 2001). Most patients with asthma are atopic, although a minority have intrinsic, nonatopic asthma that often has a later onset and a more protracted course than atopic asthma. Recent studies indicate that there are more similarities than differences in the airway abnormalities of atopic and nonatopic asthma (Humbert et al. 1999). A large body of evidence shows that allergen exposure influences the atopic phenotype, and many studies indicate that allergen or toxicant exposure during critical windows of immune system development (in utero and early infancy) may influence a sensitization process that can lead to childhood asthma (reviewed in: Landrigan 1998). Epidemiological data support the findings from these studies and highlight the role of maternal factors (Donovan and Finn 1999; Warner et al. 1998). Clearly, an interaction exists between inherited genetic characteristics and the in utero and postnatal environment, such that early toxicant exposure may predispose an individual to asthma, but postnatal exposure affects disease occurrence (Warner and Warner 2000).
The disease occurrence can also be seen along racial lines. Although asthma is a problem of all races, based on the results of the 1993-1996 National Health Interview Survey data, asthma-related morbidity is reportedly higher among black and poor children (Akinbami et al. 2002), and poverty, racism, and inequitable access to medical care have all been reported to contribute to the cause of asthma (Landrigan et al. 1998). Nonetheless, it is believed that environmental toxicants play a major role, and more than half of the more than 15,000 synthetic chemicals widely used in consumer products and dispersed in the environment remain untested for toxicity (Landrigan et al. 1998).
Was this article helpful?
If you suffer with asthma, you will no doubt be familiar with the uncomfortable sensations as your bronchial tubes begin to narrow and your muscles around them start to tighten. A sticky mucus known as phlegm begins to produce and increase within your bronchial tubes and you begin to wheeze, cough and struggle to breathe.