Drug provocation tests in hypersensitivity drug reactions.

PURPOSE OF REVIEW: Drug provocation test (DPT) is necessary to diagnose most drug hypersensitivity reactions (HSRs) due to decreased sensitivity of skin testing even when combined with in-vitro tests in immunonologic drug HSR and limited availability of these tests in nonimmunologic reaction. We review the principles and controversial issues of DPT, and recent studies using DPT as a diagnostic tool.

RECENT FINDINGS: DPT is recommended in the diagnosis of HSR to β-lactams, as well as other drug classes [such as acetylsalicylic acid-NSAIDs (ASA-NSAIDs), non-β-lactams antibiotics, heparin, glucocorticoids, and local anesthetic agents]. In view of the decreased sensitivity of skin testing, limited accessibility to new benzylpenicillin polylysine (PPL)/mixture of minor determinant (MDM) test reagents and limited availability of validated sensitive in-vitro tests, individuals who require DPT to β-lactams are increasing. The negative predictive value of allergologic work-up is very high, ranging from 94 to 98% for β-lactams and those reactions after negative tests are mostly nonimmediate and mild. Finally, DPT is recommended to ascertain tolerability of alternative compound when evaluating cross-reactivity among different classes of β-lactams, NSAIDs and glucocorticoids, and possibly iodinated contrast media.

SUMMARY: DPT is often needed when evaluating patients with suspected drug HSR. More studies regarding standardization of the various protocols are needed in order to increase its acceptance and adoption as a standard practice in the diagnostic algorithm for drug HSR.