P31Patch test reactions in the elderly

Objective:  To investigate whether application of allergic patch tests with transparent semi‐occlusive adhesive plastic foils yields higher test sensitivity than when tapes are used. To study whether such foils compared to tapes allow a shorter application time of tests.
Methods:  We applied different doses of budesonide printed on polyester squares and vehicle control squares to budesonide allergic subjects for 4 days. Each subject was tested with a set of tests both with a tape and a foil. We assessed all tests when they had been detached and additionally those applied with foils at earlier time points. All assessments were performed both visually and with a laser Doppler perfusion imaging technique.
Results:  Test sensitivity is higher with foil applications than when tapes are used and the perfusion is higher with the foils in many cases. The foils allow detachment of visually positive tests before 48 hours in some subjects, regardless of dose.
Conclusions:  Test applications with transparent semi‐occlusive adhesive plastic foils is sensitive and should be considered for application of patch tests when a short application time is important as when tests are carried out with occupationally hazardous allergens or when test substances containing allergens are expected to be irritating.