Study: Vaccine skin reactions aren’t dangerous
Getting COVID-19 can cause all manner of odd skin reactions. A new study finds some of them, including “COVID toes,” a measleslike rash and shingles also can be rare, and thankfully brief, side effects of the Pfizer-BioNTech or Moderna vaccines.
The minor reactions were seen in a database of 414 cases of delayed skin problems linked to the vaccines and reported to health care professionals. The cases were collected between December and February, before the Johnson & Johnson vaccine had been authorized, so it was not included.
None caused a life-threatening reaction, a finding the study’s senior author, Dr. Esther Freeman, found reassuring.
“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, director of global health dermatology at Massachusetts General Hospital.
“For people whose rashes started four or more hours after getting the vaccine, zero percent of them went on to get anaphylaxis or any other serious reaction,” she said. “Zero is a nice number.”
The delayed skin responses described in the study often start a day or so after vaccination but can appear as long as seven to eight days later. They are different from severe and immediate allergic reactions, which occur within the first four hours.
The findings appeared Wednesday in the Journal of the American Academy of
Dermatology. Because the cases include only those reported to a dermatological registry, it’s impossible to say how common they are across all people getting the vaccines. In general, the researchers believe them to be rare given the low numbers seen among patients.
While skin reactions to the vaccines can occur, as long as they start more than four hours after vaccination they are generally not life-threatening.
“People can feel reassured about getting the second dose of their vaccine,” said Freeman, who is the principal investigator for the international COVID-19 Dermatology Registry. “Even if you have a pretty impressive rash after the vaccine, as long as it didn’t start within four hours of vaccination you
should feel comfortable getting the second dose.”
Researchers point out that most people who get vaccinated do so without developing any reaction. The Moderna and Pfizer-BioNTech clinical trials reported rare skin reactions, and a recent study of almost 65,000 people found that anaphylaxis after vaccination was an unusual event.
Anyone experiencing severe symptoms should consult a health care professional, Freeman said.
A skin response to the first dose of a vaccine doesn’t mean you will have one to the second dose. Fewer than half – 43% – of patients who got a rash in response to their first dose of vaccine had a rash after their second.
The most commonly reported reaction was a raised, sometimes itchy red rash, often at the site of the injection, which can occur up to a week or so after being vaccinated. It has been called “COVID arm” or “Moderna arm” because about 95% of the reactions occur with the Moderna vaccine.
“COVID toes” were another rare and annoying but not life-threatening reaction. Also called pernio or chilblains, the skin sores or bumps occur on a patient’s toes and in about 10% of cases on the fingers. They can cause red or purple swelling of the digits.
An all-body rash reported by some patients, called a morbilliform rash, often is referred to as “measleslike” though it isn’t measles.
Another reaction was skin swelling in people who have had dermatologic fillers as a cosmetic treatment, though it was very rare. “If you’ve had facial filler, it doesn’t mean you shouldn’t get the vaccine,” Freeman said.
Among those who had an immediate allergic reaction to the Pfizer-BioNTech or Moderna vaccines, it was rare, and no deaths have been reported.
A study of 65,000 employees at Massachusetts General Hospital who were vaccinated with either the Pfizer or Moderna vaccine found the rate of lifethreatening anaphylaxis was 0.025%.
“That’s one-fortieth of 1%,” Freeman said. “That’s a really nice low number.”