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.