False-negative skin test AFTER positive?


My 2yo DD had her second skin test for PA today and, to our shock, tested NEGATIVE! She had her first (and only severe) reaction at daycare a little over a year ago. She went to the allergist the following week and tested POSITIVE on the skin test for PA only. Anyone else ever have a negative AFTER a positive skin test?

The doctor did order a RAST test, but we won't know the results until next week.

My biggest question is whether or not the test might have been affected by the prednisolone steriods that she's currently taking for tonsillitis and a scheduled tonsillectomy next week.

Thanks- Michele

On Aug 24, 2007

By the way - I forgot to mention that her prick test for the histamine control showed a positive wheal even while on the prednisolone.


On Sep 28, 2007

How did the RAST testing go?