Asthma test helps doctor tailor treatment

Inhaled corticosteroids are often used to treat asthma, but trying to figure out if the therapy is necessary — and at what dose — can be tricky.

Now, a new, noninvasive breath test called fractional exhaled nitric oxide, or FeNO, has taken away much of the guesswork about whether a patient should be on inhaled corticosteroids. The test is helping to guide treatment decisions and is the first to measure airway inflammation — the major underlying cause of asthma.

"With one breath into a hand-held device, physicians can measure the level of inflammation in a patient's lungs," said Dr. Stanley Fineman, an allergist at the Atlanta Allergy & Asthma Clinic. "If FeNO levels are high, that signals that the patient's lungs are inflamed and the asthma is out of control." By measuring airway inflammation, physicians can determine whether a steroid is the appropriate therapy and at what dose.

A physician typically determines whether inhaled corticosteroids are the best course of treatment, based on the severity of the patient's asthma. Traditionally, a physician will talk to patients about their history and symptoms (coughing or wheezing), perform a physical exam and testing — like lung function, to get a clearer picture of each patient's individual asthma. By measuring FeNO levels, physicians can better determine if steroids are the appropriate course of treatment and if dosage might need to be increased or decreased.

"One of the things people need to understand is that the use of corticosteroids can be lifesaving," Fineman said. "As long as you monitor the effects and the side effects, then you should be able to control any potential side effects and minimize them."

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