This summary was compiled from the tweets posted by allergists/immunologists who attended the 2013 annual meeting of the American Academy of Allergy Asthma and Immunology (AAAAI) (see the list at the end). The tweets were labeled #AAAAI. The text was edited and modified by me.David Khan, MD presented a case based approach to drug allergy. Dr. Castells also had a presentation on the topic.
Anaphylaxis during anesthesia
Anaphylaxis during anesthesia is complicated to diagnose due to the large number of drugs administered. Antibiotics, induction agents, latex are all potential triggers or perioperative anaphylaxis. Skin testing and history remain the mainstay of diagnosis for drug allergy in perioperative reactions. French literature has most robust data on concentrations to use in skin testing for intraoperative drugs. In 2/3 cases, skin testing can find causal agent in perioperative anaphylaxis.
Chlorhexidine digluconate is a popular disinfectant, and may be a cause of perioperative anaphylaxis.
Classification of adverse reactions to drugs, using the "SOAP III" mnemonic (click to enlarge the image).
Drug challenges
Clinical indications for drug challenges: in the US, we use it to rule out drug allergy.
Contraindications to drug challenge include severe cutaneous drug reactions (e.g. Stevens- Johnson), specific organ involvement (DRESS).
Many patients with negative drug challenges will have transient subjective symptoms during challenge. These patients may be experiencing drug-induced vocal cord dysfunction (VCD) Consider placebo control.
New code for ingestion challenges. 95076. At least 61 minutes, incremental graded challenge. Inclusive of E/M.
Desensitization
When do we desensitize? When there is a high suspicion of hypersensitivity, and a positive skin test.
Desensitizations generally start with 1/10,000 of target dose.
Severe reactions during beta-lactam desensitizations are rare. Same holds true for chemotherapy and monoclonal antibody desensitizations.
Aspirin desensitization
Aspirin desensitizations have a higher reaction rate, but can still be done in the outpatient setting. Combined zileuton, montelukast is most effective in reducing upper, lower respiratory response during ASA challenge, and desensitization.
Omalizumab may be end-line option for ASA-sensitive CRS with NP patients who fail ASA desensitization therapy. Source: JACI 2013
CF patients
Decreased FEV1 or transplant status is NOT contraindications to medication desensitization in patients with CF. In CF patients with severely reduced lung function (eg, pre-transplant). extended protocol (eg, 20-step) medication desensitizations are often successful.
Chemotherapy agents
Most reactions to chemotherapy agents occurred after the *last* step in a 12-step protocol. Source: Castells JACI 2008.
Dr. Castells: 1) Anaphylaxis during desensitization occurs regardless of premedication given. 2) ALWAYS send a tryptase level.
ACEI reactions
ACEI cough can last for TWO MONTHS after ACEI is removed.
Allergists are on Twitter - follow them
Allergists increased Twitter use 470% in one year - 25 allergists reached 250,000 individuals from the 2012 #AAAAI meeting (see the references here). This summary was compiled from some of the tweets posted by the following allergists:
https://twitter.com/allergistmommy
https://twitter.com/nmchase
This is a list of the allergists who used Twitter to post updates from the 2013 #AAAAI meeting. The list is open for edit, please feel free to add your own info.
I would strongly encourage you to post updates on Twitter from the CME conferences that you are planning to attend in the future. Here is how to do it: Twitter for Physicians: How to use Twitter to keep track of the latest news and scientific meetings, and share information with colleagues and patients.
Disclaimer: The text was edited, modified, and added to by me. This is one of a series of posts that will be published during the next few weeks.
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