Skin allergies after COVID-19 vaccination rare, recurs seldomly after second doses: JAMA

For the study, a team led by Kimberly G. Blumenthal, MD, MSc, co-director of the Clinical Epidemiology Program within MGH's Division of Rheumatology, Allergy and Immunology, prospectively studied 49,197 Mass General Brigham employees who received mRNA COVID-19 vaccines. At least one symptom survey was completed by 40,640 employees after the first dose of vaccine.

Skin reactions were reported by 776 (1.9%) of survey respondents after the first dose. Rash and itching (other than at the injection site) were the most common skin reactions, and the average age of those reporting skin reactions was 41 years. Skin reactions were more common in females (85%) than males (15%) and differed by race (62% white, 7% Black, and 12% Asian).

Among 609 individuals who reported skin reactions to the first dose, received a second dose, and completed a symptom survey after the second dose, 508 (83%) reported no recurrent skin reactions.

Among individuals with no skin reaction to the first dose, 2.3% reported skin reactions after the second dose, with rash and itching being the most common.

"This is the first information we have on risk of recurrence of skin reactions after dose 2 when there is a dose 1 reaction. Our findings could provide critical reassurance to people with rashes, hives and swelling after dose 1 of their mRNA vaccines," says Blumenthal.

Lead author Lacey B. Robinson, MD, MPH, an allergist and researcher at MGH, adds that skin reactions alone should not be a reason to skip the second dose, especially since most did not recur with the next dose. "For those that occur within hours of vaccination, or for severe reactions at any time, patients should see an allergist or immunologist who can evaluate and provide guidance on dose 2 vaccination," she says.