Thread by @EricMacyMD

1)There is a predictable rate of newly reported antibiotic “allergies” that will occur after all antibiotic use. Sulfonamides > penicillins > cephalosporins, macrolides, quinolones, clindamycin. #ASPchat Clinical Pearls

2)Only about 2% of individuals with a history of penicillin “allergy” will be confirmed to have an acute-onset hypersensitivity and another 2% a delayed-hypersensitivity. #ASPchat Clinical Pearls

3)The reference standard for current penicillin tolerance is an oral challenge with a therapeutic dose and 1 hour of observation to R/O acute hypersensitivity and 5 days to R/O delayed hypersensitivity. #ASPchat Clinical Pearls

4)Reserve penicillin skin testing for individuals with a history of hives or anaphylaxis within 1 hour of the first dose of the last course and clearing within 1 day. Only use Pre-Pen. #ASPchat Clinical Pearls

5)Penicillin skin testing random individuals with a history of penicillin allergy will result in up to 10+% false positives (individuals who would have tolerated an oral challenge). #ASPchat Clinical Pearls

6)In penicillin “allergy” delabeled individuals, the rate of a new penicillin “allergy” label after a therapeutic course is 2 to 4-fold higher than random individuals. If re-evaluated only about 3% will be confirmed to be currently hypersensitive. #ASPchat Clinical Pearls

7)True penicillin allergy wains with time. #ASPchat Clinical Pearls

8)True penicillin-associated anaphylaxis accounts for only about 1 in 1000 reports of a penicillin “allergy”. #ASPchat Clinical Pearls

9)There is no clinically significant cross-reactivity between penicillin, cephalosporins, and other beta-lactams. Completely removing all such warnings in EHRs is safe. #ASPchat Clinical Pearls