Anaphylaxis

Evaluation of Suspected Antibiotic Allergies

Author/s: 
Ruchi Singla, Megan C Elios, Andrew M Davis

Antibiotic-associated adverse drug reactions are often mild (eg, nausea or diarrhea) and typically occur 1 to 6 hours after drug exposure. IgE-mediated reactions cause urticaria, angioedema, bronchospasm, or, in severe cases, anaphylaxis. Cell-mediated delayed hypersensitivity can occur over days to weeks, most commonly as benign cutaneous morbilliform eruptions, although more severe manifestations, such as Stevens-Johnson syndrome, may occur.

The guideline provides evidence-based recommendations for evaluating possible drug allergy in nonsteroidal anti-inflammatory drugs, chemotherapies, immune checkpoint inhibitors, biologic agents, and excipients (inactive substances formulated with pharmaceuticals). This JAMA Clinical Guidelines Synopsis focuses on practice recommendations for antibiotic allergy evaluation.

Management of Food Allergies and Food-Related Anaphylaxis

Author/s: 
Edward G A Iglesia, Mildred Kwan, Yamini V Virkud, Onyinye I Iweala

Importance: An estimated 7.6% of children and 10.8% of adults have IgE-mediated food-protein allergies in the US. IgE-mediated food allergies may cause anaphylaxis and death. A delayed, IgE-mediated allergic response to the food-carbohydrate galactose-α-1,3-galactose (alpha-gal) in mammalian meat affects an estimated 96 000 to 450 000 individuals in the US and is currently a leading cause of food-related anaphylaxis in adults.

Observations: In the US, 9 foods account for more than 90% of IgE-mediated food allergies-crustacean shellfish, dairy, peanut, tree nuts, fin fish, egg, wheat, soy, and sesame. Peanut is the leading food-related cause of fatal and near-fatal anaphylaxis in the US, followed by tree nuts and shellfish. The fatality rate from anaphylaxis due to food in the US is estimated to be 0.04 per million per year. Alpha-gal syndrome, which is associated with tick bites, is a rising cause of IgE-mediated food anaphylaxis. The seroprevalence of sensitization to alpha-gal ranges from 20% to 31% in the southeastern US. Self-injectable epinephrine is the first-line treatment for food-related anaphylaxis. The cornerstone of IgE-food allergy management is avoidance of the culprit food allergen. There are emerging immunotherapies to desensitize to one or more foods, with one current US Food and Drug Administration-approved oral immunotherapy product for treatment of peanut allergy.

Conclusions and relevance: IgE-mediated food allergies, including delayed IgE-mediated allergic responses to red meat in alpha-gal syndrome, are common in the US, and may cause anaphylaxis and rarely, death. IgE-mediated anaphylaxis to food requires prompt treatment with epinephrine injection. Both food-protein allergy and alpha-gal syndrome management require avoiding allergenic foods, whereas alpha-gal syndrome also requires avoiding tick bites.

Allergic Reactions Including Anaphylaxis After Receipt of the First Dose of Pfizer-BioNTech COVID-19 Vaccine

Author/s: 
Shimabukuro, T., Nair, N.

On December 11, 2020, the US Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for the Pfizer-BioNTech coronavirus disease 2019 (COVID-19) vaccine, administered as 2 doses separated by 21 days.1 Shortly after, the Advisory Committee on Immunization Practices (ACIP) issued an interim recommendation for its use.2 Following implementation of vaccination, reports of anaphylaxis after the first dose of the Pfizer-BioNTech COVID-19 vaccine emerged.3 Anaphylaxis is a life-threatening allergic reaction that occurs rarely after vaccination, with onset typically within minutes to hours.4

Notifications and reports of suspected severe allergic reactions and anaphylaxis following vaccination were captured in the Vaccine Adverse Event Reporting System (VAERS), the national passive surveillance (spontaneous reporting) system for adverse events after immunization.5 Physicians at the US Centers for Disease Control and Prevention (CDC) evaluated these reports and applied Brighton Collaboration case definition criteria6 to classify case reports as anaphylaxis or not anaphylaxis. Nonallergic adverse events, mostly vasovagal or anxiety-related, were excluded from the analysis. Anaphylaxis and nonanaphylaxis allergic reaction cases with symptom onset occurring later than the day after vaccination were also excluded because of the difficulty in clearly attributing allergic reactions with delayed onset after vaccination. Because the Moderna COVID-19 vaccine was only available beginning December 21, 2020, this article focuses on the Pfizer-BioNTech COVID-19 vaccine.

During December 14 to 23, 2020, after administration of a reported 1 893 360 first doses of Pfizer-BioNTech COVID-19 vaccine (1 177 527 in women, 648 327 in men, and 67 506 with sex of recipient not reported),3 CDC identified 21 case reports submitted to VAERS that met Brighton Collaboration case definition criteria for anaphylaxis (Table), corresponding to an estimated rate of 11.1 cases per million doses administered. Four patients (19%) were hospitalized (including 3 in intensive care), and 17 (81%) were treated in an emergency department; 20 (95%) are known to have been discharged home or had recovered at the time of the report to VAERS. No deaths from anaphylaxis were reported.

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