First Detailed Look at COVID Vaccine Skin Reactions

A wide range of skin reactions has occurred following coronavirus vaccination — including some that mimic COVID-19 symptoms — but none proved to be serious, according to initial data from an international registry.

A review of 414 skin reactions associated with the Moderna and Pfizer vaccines showed a variety of rashes, eruptions, and injection-site inflammation. Less commonly, patients had episodes of zoster (shingles), herpes simplex flares, and rosacea-like reactions. A few patients developed pernio/chilblains, better known as “COVID toes.” Most of the reactions were mild and resolved on their own. No serious reactions were reported.

The findings came from the COVID-19 Dermatology Registry, a joint effort of the American Academy of Dermatology (AAD) and the International League of Dermatologic Societies. They were discussed during the recent AAD virtual meeting and published simultaneously in the Journal of the American Academy of Dermatology.

“We have been involved with following skin reactions to COVID-19 vaccines, but the paper is pretty novel in that it covers a whole range of reactions that had not been reported from vaccine clinical trials,” registry principal investigator Esther Freeman, MD, PhD, of Massachusetts General Hospital in Boston, told MedPage Today. “Understandably, the clinical trials were focused on their major endpoints and didn’t really provide a lot of detail on the skin reactions seen in patients.”

Established in March 2020 to accumulate information on cutaneous manifestations of COVID-19, the registry expanded in December to include vaccine-related skin reactions, shortly after the FDA issued the first emergency use authorizations (EUAs) for the vaccines. Registry participants collected information on the type and timing of vaccine doses and the morphology, timing, duration, and treatment of reactions.

The initial report was limited to skin reactions associated with the Moderna and Pfizer vaccines, the only two with EUAs at the time of data analysis. Of the 414 reactions documented, 83% occurred in patients vaccinated with the Moderna vaccine and 17% in patients who received the Pfizer vaccine.

Information about both vaccine doses was available for 180 patients, 29 of whom had skin reactions after both doses. Among those who received the Moderna vaccine, delayed large local skin reactions were most common, occurring in 175 of 267 (66%) patients after the first dose and 31 of 102 (30%) after the second dose.

“People were confusing these delayed reactions with cellulitis or skin infection, and so we were able to provide reassurance,” said Freeman.

Reactions that occur immediately after vaccination, or within a few hours, could be rare allergic reactions that require prompt medical attention, she added.

Local injection-site reactions occurred in 54% of patients after the first Moderna dose and 70% after the second dose. The most common manifestations of localized injection-site reactions were swelling (44% after the first dose, 68% after the second), erythema (49% and 67%), and pain (35% and 59%).

Urticaria was the next most common type of skin reaction associated with the Moderna vaccine. In most cases, the rash arose more than 24 hours after dosing (4.8% after the first dose, 4.9% after the second). An additional 2% of patients developed urticaria within the first 24 hours (all after the second dose).

Measles-like morbilliform rash occurred after the first dose of Moderna vaccine in 4.1% of patients and after the second dose in 6.9%. Erythromelalgia occurred after 5.9% of second doses, and cosmetic filler reactions occurred after 4.9% of second doses. No other type of reaction occurred in more than 1%-2% of patients after either dose.

The Pfizer subgroup represented a smaller sample size (34 first-dose reports and 40 second-dose reports), but the pattern of skin reactions was similar to that observed with the Moderna vaccine. Delayed large local reactions occurred after 15% of first doses and after 18% of second doses. Local injection-site reactions occurred after 24% and 25% of first and second doses, respectively. Frequency of the most common manifestations of local injection-site reactions, by dose, were swelling (18% and 15%), erythema (18% and 20%), and pain (24% and 18%).

Delayed urticaria appeared to occur more often after vaccination with the Pfizer vaccine (26% and 18%), as did morbilliform rash (18% and 7.5%) and flares of existing dermatologic conditions (24% and 7.5%).

The registry data included a total of eight cases of pernio/chilblains, three each after the first dose of both vaccines and two after the second Pfizer vaccine dose.

“I think this is particularly interesting because it shows that the body is mounting an immune response to the vaccine, just as it does after infection with the virus,” said Freeman.

The registry added to a recent report of zoster flare as a skin reaction associated with COVID vaccination. The registry showed a total of 10 flares, five after a first dose of Moderna vaccine, one after an initial dose of Pfizer vaccine, and four after the second Pfizer dose.

Not uncommonly, skin reactions were accompanied by systemic effects, including fatigue, myalgia, headache, fever, arthralgia, nausea, and chills.

Last Updated May 05, 2021