Sweat test with borderline values

Question

Hello,

my 4-year-old daughter took a sweat test today, since she frequently has a cough. Up until the day before the test, she was treated with antibiotics (light case of pneumonia). The result was a value of 46, which, however, has not been confirmed by the lab yet. The doctor said my daughter still had some mucus still but that the lung was ok again. I was told to call back later, and if the lab value differs from the one above, she could give the all-clear. What do you think about this? Do we have to worry?

Answer

Hello,

You are saying that your 4-year-old daughter – who has been having frequent respiratory infections with cough and most recently a mild case of pneumonia that had to be treated with antibiotics – took a sweat test, and that the result was a borderline value of 46 (mmol for chlorine?). Certainly you will want to know what to do now.

First of all, you should repeat the sweat test, in fact on both arms simultaneously. If the results are in the borderline area again, further diagnostics should be done in a specialized CF center in order to clarify this quickly. A value of 46 may very well occur in healthy people who do not have CF.

It is understandable that you are very worried now. Therefore, you should get clarification as soon as possible in a specialized center. The specialists there know which further diagnostic steps they need to suggest to you.

We wish you good luck and good test results.

Kind regards
Dr. H.-G. Posselt

03.02.2009