PEG Skin Testing in Identifying Allergic Reactions to COVID Vaccines

While there are certain genetic and environmental factors that may increase an individual's risk of developing anaphylaxis in general, there is currently no specific biomarker or genetic test that can reliably predict an individual's risk of anaphylaxis to vaccines. The decision to administer a vaccine to an individual with a history of anaphylaxis is recommended to be made on a case-by-case basis. 

Recent paper describes a case where PEG skin testing was useful in predicting an allergic reaction to BNT162b2 vaccine. 

We note that there have been some reports of successful PEG skin testing in certain non-COVID-vaccine-related cases in the past, but the reliability of this method has not been established through systematic research studies and the skin test could be life-threatening in some cases.  There is a lack of standardization in the PEG skin test procedure, including the concentration and method of application of the PEG test solution, which makes it difficult to interpret the results.

In the recent report, 30-year-old female with history of allergic rhinitis, asthma, reaction to eye cosmetics and adhesive tape (erythema, edema, and local pruritus) experienced grade III anaphylaxis immediately after application of the first dose of Pfizer-BioNTech vaccine. The patient was stratified, phenotyped and skin tests with PEG 3350 were positive. A recommendation was issued not to reapply vaccine containing polyethylene glycol and alternatives were offered.

We talked about anaphylaxis to COVID-19 vaccines in our previous posts, including fatal outcomes for a 79-year old female after Moderna vaccine, and a 27-year old female after the 1st dose of AstraZeneca vaccine and milder cases of hypertensive anaphylaxis in a 48-year-old female

While certain genetic and environmental factors may increase an individual's risk of developing anaphylaxis in general, there is currently no specific biomarker or genetic test that can reliably predict an individual's risk of anaphylaxis to vaccines. 

The reported rate of anaphylaxis to COVID-19 vaccines varies. For Pfizer-BioNTech, the reported rate was between 4.7 and 11.1 cases per million doses administered. For Moderna, the reported rate is 2.5 anaphylaxis cases per million doses administered. 


REFERENCE

Estrada-García CD, Macías-Robles AP, Cortés-Grimaldo RM, Carvajal-Alonso HL, Barreto-Alcalá M, Ramírez-Nepomuceno A, Esparza-Amaya D, Coronado-Hernández KG, Barrios-Díaz B, Campos-Téllez HH. Alergia a la vacuna Pfizer-BioNTech® demostrada mediante pruebas cutáneas [Allergy to Pfizer-BioNTech® vaccine demonstrated by skin testing]. Rev Alerg Mex. 2023 Jan 4;69(2):89-92. Spanish. doi: 10.29262/ram.v69i2.1088. PMID: 36928249.


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