The Pfizer and Moderna COVID-19 vaccines have been found to have side effects that include odd skin reactions such as rashes and discolored, swollen toes known as “COVID toes” that are worrisome to patients, but a new study found they usually don’t last long.

According to USA Today, the side effects were noted in 414 cases collected between December 2020 and February 2021, before the one-shot Johnson & Johnson vaccine was authorized, so it doesn’t appear in the database.

The study’s senior author, Dr. Esther Freeman, said that none of the reactions were life-threatening.

“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, an assistant professor of dermatology at the Harvard Medical School and director of global health dermatology at Massachusetts General Hospital.

The findings were published Wednesday in the Journal of the American Academy of Dermatology. According to USA Today, the delayed skin responses found in the study usually began a day or so after receiving the vaccine, but some people reported that the dermatological side effects appeared a week later.

Freeman, who is also the principal researcher in the global COVID-19 dermatological registry previously noted that people also developed a red, welted rash around the vaccination site after getting the Moderna jab.

According to Insider, the reaction is harmless, and while it can cause itching or aching, it usually subsides within 24 hours to a week. However, it may scare some people from getting their second shots, say experts.

So far, the reported number of cases has been limited says Freeman, adding that she believes many more incidents have not been registered.

The medical term for the rash is “delayed cutaneous hypersensitivity.” Lay people have been calling it “COVID arm.” Freeman notes. She said that a small percentage of people in the Moderna clinical trials reported rash reactions.

“It doesn’t mean you should get Pfizer instead of Moderna,” she said. “It’s not such a big deal.”

Experts say that more women than men appear to suffer COVID arm, and more people in their 30’s and 40’s are afflicted. Since most of the first people to get the Moderna vaccine were healthcare workers who tend to be female, this could be a reason for the discrepancy. Frontline workers also fall into the age category that are seeing the most reactions, so that is not unusual, said Dr. Tom Shimabukuro, of the COVID-19 Vaccine Task Force Safety Team.

What is unusual is that the rash typically appears 5 to 9 days after the first shot, and since allergic reactions often get worse with exposure, experts are worried that the second shot of the vaccine will elicit a more severe reaction.

Dr. Praveen Buddiga, an allergy and immunology specialist in Fresno, California, says he sees this hypersensitivity in 2-9% of patients receiving shots.

“Just use the method of putting ice on it, drink a lot of water, and stretch that arm and it’ll go away in less than 24 hours,” he said, according to Insider.