Table 5.
Similarities and differences between Americans and Europeans in the management of drug hypersensitivity
| American perspective | European perspective | |
|---|---|---|
| General rules for management | Based on clinical evaluation For immediate reactions, STs are applied first; if they are negative, DPT is performed unless contraindication exists STs are not recommended for non-immediate reactions No allergy tests are recommended in history of severe reactions* Desensitization is recommended in indicated cases |
Allergy tests are strongly recommended if there are no contraindications. STs are applied first; if they are negative, DPT is performed unless contraindication exists Selection of STs depends on underlying mechanisms (SPTs/IDTs for immediate reactions, PTs and delayed-reading IDTs for non-immediate reactions) Desensitization is recommended in indicated cases |
| Immediate reactions | ||
| SPTs/IDTs | Recommended for BLs, other antibiotics, NMBAs, chlorhexidine, chemotherapeutic agents, insulin, heterologous antisera, and streptokinase at non-irritating concentrations | Recommended based on sensitivity and specificity of the tests BLs, pyrazolones, NMBAs, chlorhexidine, LAs, RCM (strong recommendation) Should be performed at non-irritating concentrations |
| In vitro tests | Not recommended | Serum specific IgE assays are recommended for BLs, NMBAs, and chlorhexidine BAT is recommended for BLs and NMBAs (complementary to sIgE assays), as well as for pyrazolones, fluoroquinolones, and RCM |
| Non-immediate reactions | ||
| General rules for management | PTs and IDTs are not recommended routinely | PTs and IDTs are recommended routinely PTs are performed first; if negative, delayed-reading IDTs are performed if no contraindications exist |
| PTs | May have a role in delayed DHRs, such as MPE, AGEP, and FDE | Recommended In severe cases, lower drug concentrations are recommended |
| Delayed-reading IDTs | Not recommended | In severe cases, such as DRESS, AGEP, and TEN/SJS, can be performed after negative PTs and at higher drug dilutions |
| In vitro tests | Pre-screening with certain HLA alleles before introduction of abacavir and carbamazepine Other tests (e.g., LTT and ELISpot) are not recommended |
Pre-screening with certain HLA alleles before introduction of abacavir and carbamazepine Other tests (e.g., LTT and ELISpot) arenot recommended |
| Non allergic drug hypersensitivity | ||
| Skin tests | Not recommended | Not recommended |
| In vitro tests | Not recommended | Not recommended |
| Drug provocation tests/challenges | ||
| Indication | To exclude DHR in non-suggestive histories or provide safe alternatives | To exclude DHR in non-suggestive histories or provide safe alternatives To confirm diagnosis |
| Methods | Similar contraindications and precautions | Similar contraindications and precautions |
| Comment on a negative test result | “Patients who tolerate a graded challenge are considered to not be allergic to the drug and are not at increased risk for future reactions compared with the general population” | “A negative test does not prove tolerance to the drug in the future, but rather that there is no DHR at the time of the challenge and to the doses challenged” |
DPTs drug provocation tests, STs skin tests, SPTs skin prick tests, IDTs intradermal tests, PTs patch tests, BP benzylpenicillin, NMBAs neuromuscular blocking agents, LAs local anaesthetics, RCM radio contrast media, BLs β-lactams, BAT basophil activation test, DHRs drug hypersensitivity reactions, MPE maculopapular exanthema, DRESS drug reaction with eosinophilia and systemic symptoms, SJS/TEN Stevens–Johnson syndrome/toxic epidermal necrolysis, AGEP acute generalized exanthematous pustulosis, FDE fixed drug eruption, sIgE specific IgE, LTT lymphocyte transformation test, ELISpot enzyme-linked immunosorbent spot
aDRESS, TEN/SJS; AGEP, severe anaphylactic shock within the last year