Thread by @OBsleepmerchant

@LondonAllergy presents on a topic we don’t hear much about (follow her & @LouiseSavic for fascinating insights): LOCAL ANESTHETIC ALLERGY at #RAUK23

Topic equally important to #OBAnes audience (@OAAinfo @noolslucas - #OAA3dc?) and I’m sure #SOAPAM2023 audience will enjoy!

The allergist team are ready and waiting for your referral, poised to leap into action with different testing modalities. When would they do a drug challenge? To test cross reactivity, exclude allergy and confirm diagnosis #RAUK23

Skin testing (a positive latex allergy) includes a negative spot (saline to rule out dermographia) & a positive histamine spot to check for antihistamines in system)

Intradermal testing uses low dilutions for specific drugs. Here a 1:10,000 dilution of sugammadex illicited a… twitter.com/i/web/status/1…

Perioperative anaphylaxis is the crime scene of allergy. The usually suspects based on NAP6: antibiotics = #1 (psycho-teico/ teicoplanin). Interestingly NO cases involved local anesthetic - does allergy to local even exist? #RAUK23

@LondonAllergy describes drugs as having different personalities where allergy is concerned. Penicillin is an honest drug - if you’re going to react, you will, PCN turns itself in. Teicoplanin is more of an OJ - it’s going to take a LOT of effort to catch and convict psycho-teico… twitter.com/i/web/status/1…

A pristine crime scene is important. Good documentation and timely evidence is essential. #RAUK23

Case history 1: dental patient. Allergy to articaine based on skin testing, but only available in epinephrine/ adrenaline combo. Question always arises whether it’s the drug or the preservative. To exclude allergy, a challenge was performed. #RAUK23

Case 2: A lot of suspects. Negative skin tests to local anesthetics. What do you do now? Say not allergic? Do a challlenge? Split audience poll - probably would have had same result in room of allergists to be fair. Lidocaine challenge - photo not for twitter - very positive!… twitter.com/i/web/status/1…

Case history 3: typical preanesthetic clinic patient - remote, unclear history. Patient told allergic to local, so had had a lots of dental work without it - sheesh!Patient requested referral because extractions was a bridge too far. Positive intradermal to lidocaine. So what… twitter.com/i/web/status/1…

Thankfully negative challenge tests! Hope he got de-labelled effectively! #RAUK23

Conclusions: local anesthetic allergy is RARE (zebra analogy wouldn’t work in South Africa, but unicorn inappropriate as DO exist), local anesthetics are Machiavelli-like in terms of allergy: tricky; allergy testing is not a simple yes/no test; timing (and documentation) is… twitter.com/i/web/status/1…

Summary slide! Collaboration is essential. Join the Perioperative Allergy Network if this is topic interests you #RAUK23