Researchers studied 414 patients with vaccine skin reactions from Dec. 24, 2020, to Feb. 14, 2021. The median age of the patients was 44, 90% were female, and 78% were white, the study says. The cases were reported by doctors including dermatologists, nurses, and other health care workers.
“People can get full-body rashes, and that can be surprising and a little scary, but these patients did extremely well, recovered, and were able to go back and get their second dose,” said Freeman, who is director of global health dermatology at Massachusetts General Hospital. “For people whose rashes started 4 or more hours after getting the vaccine, 0% of them went on to get anaphylaxis or any other serious reaction. Zero is a nice number." Skin reactions can occur about a week after a shot, the study said. Any reaction -- on the skin or otherwise -- that occurs less than 4 hours after the shot may be an allergic reaction and is a cause for alarm, doctors say.
The most common reaction was a rash at the injection site, sometimes called COVID arm or Moderna arm. About 95% of the reactions in the study occurred to people who got the Moderna vaccine. Few people who had this reaction after the first shot had it after the second, the study said.
Redness and swelling on the feet and hands, known as COVID toe, also occurred in a few patients. It’s uncomfortable, “but it’s not a reason to not get the second dose,” Freeman told USA Today. Other reactions were an all-body rash often described as “measles-like;” shingles outbreaks in people who had chickenpox as children; and skin swelling in people who have had dermatologic fillers as a cosmetic treatment. “If you’ve had facial filler, it doesn’t mean you shouldn’t get the vaccine,” Freeman said. People can feel reassured about getting the second vaccine dose, she said. “Even if you have a pretty impressive rash after the vaccine, as long as it didn't start within 4 hours of vaccination you should feel comfortable getting the second dose,” she said. Clinical trials on the Moderna and Pfizer vaccines reported few cases of skin reactions. The study did not include the single-dose Johnson & Johnson vaccine, which had not been approved at the time of the study.