Apr 6, 2012

What Is the Scenario of the Rest of Atopic Diseases?

Other than analyzing asthma, a European study (SCARPOL) that was conducted four times between 1992 and 2001, revealed evidence of stabilizing asthma and hay fever, but with a predominant increase in atopic eczema in girls that was stable in boys.
The same tendency was found in the Aberdeen evaluation when considered up to 2004. There, the three atopic illnesses demonstrated a stable prevalence that was a pattern in the past 10 years, with a continuous increase present in girls that makes no sex difference at the end. As in the former study, when evaluating
eczema, females were more prevalent.
However, an Italian evaluation demonstrated an increasing trend from 1994 to 2002 in wheezing, allergic rhinoconjunctivitis and atopic eczema in both 6- to 7-year-old and 13- to 14-year-old populations, except for wheezing in the last group.
A global time trend analysis of prevalence in rhinoconjunctivitis symptoms evidenced yet again a smooth increase, being more evident in LMIC and in the older age group, suggesting that environmental influences in the development of allergy may not be limited to early childhood.
Related to these asseverations, a recent evaluation in the tendency of aeroallergen sensitization for 25 years (from 1976–1977 to 1999–2001) evidenced a significant increase in the prevalence of sensitivity as well as in the mean age of allergic patients. Again, ISAAC is the option to have a global vision. A recent publication of a worldwide comparison of two phases in 6- to 7-year-old and 13- to 14-year-old populations, using the same methodology both times with a mean of 7 years of difference, allowed to evidence several projections of concern: (a) In 6- to 7-yearold, an incremental tendency in asthma, rhinoconjunctivitis, and eczema was observed in Asia-Pacific, India, North America, Eastern Mediterranean, and Western Europe.  In 13- to 14-year-old, this augmentation was evidenced in Africa, Asia-Pacific, India, Latin America, and Northern and Eastern Europe. (c) In asthma at 6- to 7-year-old, more centers reported increase of prevalence, while in the 13- to 14-year-old group, almost equal centers reported up and down tendency.

Those having larger prevalence in the first phase tend to have a decrease in the third phase and vice versa. (d) For allergic rhinoconjunctivitis, most centers at both ages. Changes (delta) and 95% confidence interval in prevalence of wheezing, atopic rhinoconjunctivitis, and atopic eczema in the past 12 months, reported by parents of children 6–7 years of age (left) and by adolescents 13–14 years of age (right) in six areas of Italy.

Is the Prevalence of Allergy Continuously Increasing?
For atopic eczema, the 6- to 7-year-old participants showed increased tendency in average, while in the 13- to 14-year-old samples, such tendency was not that evident. Taking all disorders together, the younger group had an increase from 0.8% to 1%, and the older one from 1.1% to 1.2%.
We can then preliminarily conclude that globally, there is still a growing prevalence of atopic disorders, predominantly in developing regions of the planet.

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