One early hypothesis for the increase in respiratory allergies was that they could be a result of air-borne allergens, such as dust mites, in unhygienic house. The theory that unhygienic environments caused allergies is based on a study of 120 infants. The study of the infants was designed such that one group of parents was set as a control and were not taught anything about hygiene. In contrast, the other set of parents were taught how to keep their home clean and thus free of allergens like dust mites. The results of the study indicated that the infants of the control parents, who were not taught how to keep a hygienic home, were more often diagnosed with respiratory allergies (Nesse, Williams, 1994). One might well believe based on studies such as this that allergens such as dust mites are the cause of allergies. The study seems to explain the increase in allergies, especially since modern house are more likely to contain allergens due to the carpeting, drapery, and other textiles which provide an optimal environment for dust mites. The evidence presented by the study logically suggests therefore that allergies have been increasing because over the past one hundred years humans have been increasingly moving into dust mite ridden …show more content…
One earlier hypothesis held that contemporary highly mobile societies may expose children to a greater diversity of bacterial diseases and “miscellaneous allergens” and that this somehow might cause children to develop allergies (Nesse, Williams, 1994). While a greater amount of travel throughout early life will expose children to a greater number of pathogens and allergens, it is no longer thought that exposure to pathogens is a cause of allergies. Contrarily, current research aligned with the hygiene hypothesis shows how exposure to microbes decreases the risk of allergies. In fact, children who are more exposed to various microbes are generally healthier in relation to whether or not they have allergies. A children conducted by Maria Yazdanbakhsh determined that long-term helminth infections are inversely correlated with allergies (Yazdanbakhsh, et al. 2000). A similar study examined African children with and without the parasite schistosoma haematobium and found that those infected with the parasite were less likely to test positive on a skin test for allergies to dust mites (Biggelaar, Van Ree, Rodrigues, Lell, Deelder, Kresner, Yazdanbakhsh, 2000). The two studies both exemplify how exposure to certain decreases the prevalence of allergies. One of the first to posit that infection by helminthes was related to the prevalence of allergies was