Dust Mites and Cockroaches

The National Academy of Sciences (NAS) stated in 2000 that there is sufficient evidence of causal relationship between exposure to house dust mite allergen and the development of asthma in susceptible children (National Academy of Sciences 2000), and good correlation has been shown between early high level exposure to house dust mite and the subsequent increase in the prevalence and severity of asthma (Sporik et al. 1990). Moreover, in spite of many nonasthmatics testing positive in skin tests for dust mite sensitivity, early sensitization has been associated with a greater probability of the persistence of bronchial hyperresponsiveness and symptoms of asthma in late childhood and adolescence (Peat et al. 1990).

Similarly, cockroach antigen exposure is known to elicit a strong IgE response from B cells to induce sensitization, and the NAS has reported that 1.) sufficient evidence of causal relationship exists between cockroach (CR) allergen exposure and exacerbation of asthma in individuals specifically sensitized to CR, and 2.) there is limited or suggestive evidence of an association between CR exposure and the development of asthma in preschool-age children (National Academy of Sciences 2000).

Interestingly, the season of birth also seems to be relevant to CR antigen sensi-tization. The link made by authors Sarpong and Karrison is between CR sensitization and children born in winter, when certain viral infections are also common (Sarpong and Karrison 1998). While no studies have identified a link between infant wheezing with rhinovirus infections and development of asthma, since there is an increased incidence of respiratory syncytial virus (RSV) infections in winter, the authors have speculated that RSV (or other virus) infections concomitant with CR Ag exposure may promote IgE sensitization and the induction of asthma. Although this link is controversial (Roman et al. 1997), active research into these sorts of relationships holds the promise of unraveling some of the complexity involved when exploring the links between neonatal exposures, elevated IgE levels, infant wheezing, and the actual development of asthma.

Coping with Asthma

Coping with Asthma

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.

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