Some children who have asthma may also have peanut allergies but not know it, according to a new study.

The new results show that children with asthma may benefit from testing for peanut sensitivity, the researchers said.

"I think if a child with asthma is having difficulty controlling their symptoms — wheezing and coughing — that their parents may want to think about getting them tested for peanuts and other sensitivities, just to see if that may be contributing to why [their asthma] can't be controlled," said study author Dr. Robert Cohn of Mercy Children's Hospital in Toledo, Ohio.

In the study, researchers examined health data from 1,517 children with asthma who were treated at the pediatric pulmonary clinic at their hospital. The researchers looked at whether the children had been diagnosed with a peanut allergy, and whether they had undergone a blood test for antibodies that would show an allergic reaction to peanuts. [9 Weirdest Allergies]

Of all children, 665 had undergone blood testing for peanut allergy, and 22 percent of those children tested positive for peanut sensitivity. However, about half of those children and their families had not suspected the kids had allergies to peanuts.

Peanut allergies can severely affect the health of children with asthma. In a study published in 2010 in the Journal of Pediatrics, researchers found that the rate of hospitalization of children with asthma and peanut allergies was twice as high as the rate among children with asthma who did not have peanut allergies, Cohn said.

It's possible that having a peanut sensitivity may actually make kids' asthma symptoms worse, Cohn told Live Science.

Another reason why children with asthma should be tested for peanut allergies is that certain asthma medications should be avoided in kids with peanut allergies, the researchers said.

Parents may not suspect their child has a peanut allergy because many of the allergy's symptoms — such as shortness of breath, wheezing and coughing — may mirror those of an asthma attack, Cohn said.

Cohn said he is not sure about what mechanism might underlie a connection between asthma and peanut allergies. More research is needed to investigate this, he said.

The prevalence of peanut allergies in general is on the rise according to the Centers for Disease Control and Prevention, Cohn said.

The study was presented May 17 at the American Thoracic Society (ATS) 2015 International Conference in Denver.

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