Posted: February 4th, 2011 - 7:28am
Source: Reuters

NEW YORK -- Peanut allergies may be less common than previously believed, according to a new study based on allergy diagnoses in England.
However, the study also found that while the proportion of the population that's affected by peanut allergies -- that is, the prevalence -- is small, it has grown over time.
In recent years, parents and researchers alike have become more concerned about peanut allergies. Previous studies have shown that in some parts of the world, as many as two out of every 100 kids might have peanut allergies. The current study, however, found rates only a tenth of that, even in age groups most likely to have allergies.
Part of the difference between this study and previous ones may be in the way rates of allergy were calculated.
"Overall, the 'true' prevalence of peanut allergy is likely to lie somewhere between these various estimates," Dr. Aziz Sheikh, one of the paper's authors from the University of Edinburgh in Scotland, told Reuters Health by email.
For their calculations, Sheikh and his colleagues analyzed information from a database of all diagnoses by general practitioners in England between 2001 and 2005. The database included more than 400 practices treating almost 3 million patients.
On average, among kids under 15, one or two out of every 1,000 had received a diagnosis of peanut allergy at some point. The highest rates were in boys ages 5 to 9.
In the entire study population, including adults, about two out of every 4,000 people had a peanut allergy recorded by a general practitioner in 2005 - a doubling of the allergy prevalence in 2001, when it was about one in every 4,000 people.
By the end of the study, there were about 26,000 cases of diagnosed peanut allergy among all practices according to the findings, which are published in The Journal of Allergy and Clinical Immunology.