Late patch-test reactions to budesonide need not be a sign of sensitization induced by the test procedure.

Patch-test sensitization may be suspected when a flare-up is seen at a test site at least 10 days after the test application. We describe two patients allergic to budesonide who were only diagnosed at patch-test readings on day 10 and day 13, respectively. The patients were patch-tested to a standard series including two corticosteroid mixes and their three constituents in petrolatum, namely, budesonide, tixocortol pivalate, and hydrocortisone-17-butyrate, at differing concentrations. In both patients, positive reactions to the mixes were seen on day 6 or day 7, but positive reactions to the budesonide preparations at 0.1% and 0.002% were not seen on the first or second ordinary reading day, day 3 or 4, and day 6 or 7, but no positive reactions to both budesonide preparations were seen on day 10 and on day 13, respectively. Not all late patch-test reactions represent patch-test sensitization, at least not to budesonide.