Allergy to polyethylene glycol/macrogol following dental surgery

Abstract Background Polyethylene glycols (PEGs) are polyether compounds widely used as excipients within the pharmaceutical industry. PEG allergy is rare but increasingly reported as an unexpected cause for anaphylaxis including to the mRNA COVID‐19 vaccines. Presentation is usually with anaphylaxis to multiple unrelated drugs/products. Case Presentation We report a case of a 25‐year‐old man who had allergic reactions following root canal treatment with Odontopaste and a second reaction after a single dose of phenoxymethylpenicillin (PEG 6000). Allergy investigations confirmed PEG allergy. Conclusion All dental healthcare practitioners should be aware of a potentially life‐threatening allergy to PEG, an excipient often overlooked during investigation of anaphylaxis.