Becuase both conditions exhibit similar symptoms, many children with asthma - and their families - do not realise they could be allergic to peanuts, the researchers said.
They tested over 660 children with asthma and found that 22% tested positive for peanut sensitivity after undergoing specific IgE testing.
The families of 53% of these children did not suspect their child could be allergic to peanuts.
Test for peanut sensitivity
The results, presented at the American Thoracic Society conference 2015, suggest that children with asthma could benefit from peanut sensitivity screening, ‘especially when control is difficult to achieve’.
Some asthma medicines ‘should be avoided’ in children with peanut allergy, they added.
Lead author Dr Robert Cohn said: ‘Many of the respiratory symptoms of peanut allergy can mirror those of an asthma attack, and vice versa. Examples of those symptoms include shortness of breath, wheezing and coughing.
‘This study demonstrates that children with asthma might benefit from a test for peanut sensitivity, especially when control of wheezing and coughing is difficult to achieve. If a physician is having this problem, or if a parent notices it in his or her asthmatic child, they should consider testing, even if they believe their child is not sensitive to peanuts.’