6.2.b. Provocation tests
Because of high specificity and limited sensitivity of skin tests, DPT
should be performed in case of a negative result, despite a compatible
medical history. Several prospective studies and retrospective case
series, but also a high number of single case reports, have performed
single-blind placebo-controlled DPTs with
PPIs.3,17-19,22-23,37,42,45,53-56,57-60 Only
exceptionally, patients were also provoked with the skin test-positive
culprit PPI to confirm specificity.3,22,56
Furthermore, DPTs have been performed to identify tolerance to
alternative PPIs for any future hiring needs and to study PPI
cross-reactivity.3,17-19,22-23,37,42,45-46,53,57-58,60-61.
A placebo-controlled approach has been performed in many studies, often
with placebo capsules or tablets on the first day and the verum on the
second day. In addition, Laguna et al. performed a two-day course at
maximum dosage if patients tolerated the suspected PPI administered
during the DPT.19
During the DPT the titrated doses were administered at 30 or 60-minute
intervals as shown in Table 3.