Positivity criteria were defined by the occurrence of clinical objective
signs, such as urticaria, angioedema, rash, bronchospasm, hypotension,
oxygen saturation below 90% or 20% fall in FEV1, one study also
mentioned a 20% change in heart rate.3,17 Immediate
HSRs with delayed onset may occur with PPIs.18 Most
PPIs are slow-release and dose titration is challenging due to the
formulation and potential loss of drug function. Consequently, the TF
suggests prolonged observation of ≥3 hours after the last step of an
oral DPT with PPI.