Patients with chronic recurrent wheals are most commonly diagnosed with chronic spontaneous urticaria, although a number of autoimmune, autoinflammatory and malignant diseases can be suspected based on certain "red flags". These "red flags" are wheal duration of >24 hours, postinflammatory hyperpigmentation, systemic symptoms such as arthralgia and fever and/or elevated inflammatory markers. Herein, we detail a case of an adult patient initially diagnosed with CSU, discussing possible differential diagnoses and outlining options for treating the patient once a diagnosis has been established. We highlight a need for a careful examination of laboratory and histological findings and other investigations including serum immunofixation electrophoresis and genetic testing.

This guidance updates 2021 GRADE (Grading of Recommendations Assessment, Development and Evaluation) recommendations regarding immediate allergic reactions following coronavirus disease 2019 (COVID-19) vaccines and addresses revaccinating individuals with first-dose allergic reactions and allergy testing to determine revaccination outcomes. Recent meta-analyses assessed the incidence of severe allergic reactions to initial COVID-19 vaccination, risk of mRNA-COVID-19 revaccination after an initial reaction, and diagnostic accuracy of COVID-19 vaccine and vaccine excipient testing in predicting reactions. GRADE methods informed rating the certainty of evidence and strength of recommendations. A modified Delphi panel consisting of experts in allergy, anaphylaxis, vaccinology, infectious diseases, emergency medicine, and primary care from Australia, Canada, Europe, Japan, South Africa, the United Kingdom, and the United States formed the recommendations. We recommend vaccination for persons without COVID-19 vaccine excipient allergy and revaccination after a prior immediate allergic reaction. We suggest against >15-minute postvaccination observation. We recommend against mRNA vaccine or excipient skin testing to predict outcomes. We suggest revaccination of persons with an immediate allergic reaction to the mRNA vaccine or excipients be performed by a person with vaccine allergy expertise in a properly equipped setting. We suggest against premedication, split-dosing, or special precautions because of a comorbid allergic history.