Baseline patch testing is the use of a test that determines the sensitivity of a patient prior to the exposure of a patient to a known allergen in medicine. Extended baseline patch testing is the use of the same test following the initial exposure, and is essential for safer repeated exposure (Özkaya and Kılıç, 2018). Polyethylene glycol (PEG) is a compound that is present in many medical and pharmaceutical products, including the mRNA vaccines produced by Pfizer and Moderna.
PEG is used in these vaccines to encapsulate the mRNA encoding an mRNA molecule stabilized spike protein – and is suspected as a cause of severe allergy-like reactions (See Suspicions grow that nanoparticles in Pfizer’s COVID-19 vaccine trigger rare allergic reactions). These vaccines are the first ever to include PEG.
PEG sensivity, which can range from mild to life-threatening, has been recognized for decades (See “Immediate allergic reactions by polyethylene glycol 4000: two cases”). PEG sensitivity is widespread, due to is inclusion in drugs, cosmetics, and food (See: Immediate hypersensitivity to polyethylene glycols in unrelated products: when standardization in the nomenclature of the components of drugs, cosmetics, and food becomes necessary). PEG and other glycols to which sensitivity is known is commonly found in products for wound dressings, and those used to ease constipation, including rinses and suppositories, and in colonic preps prior to colonoscopy. PEG is listed among compounds that may have a negative public health impact (See: Contact Allergy—Emerging Allergens and Public Health Impact), because its prevalence is much higher than previously suspected (See: Immediate Hypersensitivity to Polyethylene Glycols and Polysorbates: More Common Than We Have Recognized). Increasing from past lower levels, approximately 70% of Americans may already be sensitized to PEG (See “Components of mRNA Technology ‘Could Lead to Significant Adverse Events in One or More of Our Clinical Trials,’ says Moderna” (Children’s Health Defense) and “Analysis of Pre-existing IgG and IgM Antibodies against Polyethylene Glycol (PEG) in the General Population“)
The mechanisms by which PEG causes anaphylaxis is known (See: Polyethylene Glycol Is a Cause of IgE-Mediated Anaphylaxis). Skin prick tests have been used to rule in PEG sensitivity (See: Immediate allergic reactions by polyethylene glycol 4000: two cases).
I have two main points to share;
(1) Test Your Patients. While reports to date of PEG sensitivity associated with anaphylaxis are rare, that may be due to ascertainment bias and under-reporting. I am calling on ethical physicians to adopt as standard of care skin prick or patch testing should be conducted to screen people away from vaccines that contain PEG, including COVID19.
Similarly, patch testing for aluminum sensitivity should be conducted prior to the administration of any aluminum-containing vaccine. Cases of neurological conditions that emerge following vaccination should be investigating using skin-prick or patch testing for known allergens. Patients with severe reactions to COVID19 should be studied for cross-reactive antibodies responsible. Future exposures should be avoided.
(2) Prediction: Because PEG is included in the COVID19 vaccines, we can expect when it is administered in individuals who accept aluminum-containing vaccines that PEG sensitivity will skyrocket. While aluminum is not used in the COVID19 vaccines, aluminum hydroxide is used routinely both as a vaccine adjuvant and to induce autoimmunity in animals to test pharmaceuticals for efficacy against autoimmune conditions at doses that are, by my calculations, well within the per-body weight adjusted doses required by the CDC’s pediatric vaccine schedule. It is reasonable to expect that people who receive, say, both a TdaP vaccine and a COVID19 vaccine in the same season might be at higher risk of PEG-sensitivity induced anaphylaxis.
Extended baseline testing for PEG and aluminum sensitivity should occur throughout the life of those who choose to vaccinate against COVID19, and those who choose to accept aluminum-containing vaccines.
Aluminum testing is part of a metals allergen test – see for example, this link.
Özkaya E, Kılıç S. Polyethylene glycol as marker for nitrofurazone allergy: 20 years of experience from Turkey. Contact Dermatitis. 2018 Mar;78(3):211-215. doi: 10.1111/cod.12931. Epub 2017 Nov 28. PMID: 29193145.