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Allergies To Pets Linked To Persistence of Asthma As Children Age

Allergies To Pets Linked To Persistence of Asthma As Children Age
Asthma persisted among girls, and teens who had severe allergies or were allergic to pets as children. Creative Commons

Asthma and allergies are very much related, since allergic reactions can often trigger the symptoms of an asthma attack. Because of this, many kids who have a severe case of allergies or are allergic to pets may not "outgrow" asthma, a new study says.

"Asthma is a dynamic condition, which often remits but also frequently relapses," lead author of the study, Dr. Martin Andersson, of the Obstructive Lung Disease in Northern Sweden studies, told Reuters.

Asthma's Persistence Into Young Adulthood

Dr. Andersson and his team of researchers began the study in 1996, when they surveyed the parents of 248 Swedish children, ages seven and eight, about their children's asthma. Each year thereafter, the researchers checked back with the parents until their children turned 19 — there were 205 participants by the end of the study.

Of these participants, the researchers found that 43 of them, or one in five, had gone into remission. Remission was defined as going three or more years without wheezing or using an inhaler, or any other form of medication. As for the other teens, 84 had persistent asthma and 78 had periodic asthma. Being male and having no allergies to pets more than doubled the chances of remission.

Other factors, such as damp housing, living in a rural area, and a family history of asthma, had no effect on the teens, the researchers said.

"Sensitization to furred animals and a more severe asthma at age seven and eight years were both inversely associated with remission," Dr. Andersson said.

Still with asthma affecting, nearly 7.1 million children in the U.S., it is unknown how it begins or how to cure it, hence why doctors call "outgrowing" asthma remission. Although remission rates haven't been studied in-depth, the researchers say that some reports on young adults range from 16 to 60 percent.

"This study can give parents some hope, but there's no guarantee for any child," Dr. Jennifer Appleyard, chief of allergy and immunology at St. John Medical Center in Detroit, told HealthDay. "Really, the glass is half full. There's a good chance you'll outgrow it, but there's also a really good chance you won't, especially if you have allergies too."

A Genetic Mutation That Causes Allergies

There may be hope, however, because a study recently found that a major genetic abnormality could be causing allergies and asthma, as well as a number of other related conditions, according to Time.

Researchers studying Marfan and Loeys-Dietz syndromes, two rare tissue disorders, found that a mutation in the protein, transforming growth factor-beta (TGF-beta), contributed to the syndromes along with other mutations. However, they found that the mutation in TGF-beta could also contribute to the immune responses that occur when someone has an allergic reaction. Coincidentally, many patients with Marfan or Loeys-Dietz also have allergies.

"Disruption in TGF-beta signaling does not simply nudge immune cells to misbehave but appears to singlehandedly unlock the very chain that eventually leads to allergic disease," Dr. Harry Dietz, cardiologist at John's Hopkins Children's Center and the study's author, said in a statement.

The results of the study could lead to new treatments for allergies, and by association, asthma.

"One of the hurdles in trying to develop new treatments for allergies is pinpointing the key signaling pathways we need to target," Dr. Pamela Frischmeyer-Guerrerio, an immunologist at Johns Hopkins and co-author of the study, told HealthDay. "TGF-beta really seems to be central to one of the key pathways that underlie the development of all forms of allergic disease."

Sources:

Andersson M, Hedman L, Bjerg A, et al. Remission and Persistence of Asthma Followed From 7 to 19 Years of Age. Pediatrics. 2013.

Frischmeyer-Guerrerio P, Guerrerio A, Dietz H, et al. TGFβ Receptor Mutations Impose a Strong Predisposition for Human Allergic Disease. Science Translational Medicine. 2013.

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