Table of ContentsView AllTable of ContentsSymptomsLump on ArmWhy Rash HappensBooster Shot RashDurationTreatmentWhy Get VaccinatedWhen to Seek Care
Table of ContentsView All
View All
Table of Contents
Symptoms
Lump on Arm
Why Rash Happens
Booster Shot Rash
Duration
Treatment
Why Get Vaccinated
When to Seek Care
Unlike immediate vaccine reactions—like anaphylaxis—COVIDarm rash is generally harmless and resolves with minimal treatment.However, if a reaction worsens or causes additional symptoms you may need to contact a healthcare provider.
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Symptoms of COVID Arm
COVID arm rashis a reaction that occurs after a COVID-19 vaccination. The rash forms a few days to a week after the injection.It tends to be more common after the Moderna COVID-19 vaccine but may happen with the Pfizer vaccine as well.
The symptoms of COVID arm rash include:
The rash may be small, just covering the injection site. However, it can also be quite large, extending over most of the arm. Reports of rash size have varied from study to study.
What Causes a Lump After Vaccination?
The lump can be a good sign that the body is makingantibodiesagainst the virus.
Less common is a nodule that develops at the injection site. They are firm and about the size of a pea. There is no redness or pain, and they generally go away without treatment.
What Causes COVID Arm Rash?
COVID arm happens because of a hyperactive immune response to the vaccine. When theimmune systemsenses the vaccine, it builds up defenses to fight the COVID-19 virus, which is exactly the purpose of the vaccine.
However, for reasons unknown to researchers, some people have a more robust immune response to the vaccine and develop COVID arm rash. Interestingly, a 2021 case report described that the development of COVID arm rash had no relation to the person’s medical history orallergies.
Can COVID Arm Rash Happen After a Booster Shot?
COVID arm rash can happen after a booster shot.
In a 2021 case study, researchers looked at 15 people who developed a COVID arm rash with their first vaccination. Eleven of those people also had reactions to thesecond dose. Most people developed a reaction sooner after their second dose than they did with the first dose. The duration of the reaction to the second dose was similar to the duration with the first vaccine dose.
For those who have experienced COVID arm rash, your healthcare provider may recommend getting the next shot in the other arm.
Reporting Vaccine Side EffectsIt’s important to report any vaccine reaction to the Vaccine Adverse Event Reporting System (VAERS). This is a registry that helps the U.S. Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) track any new or unusualside effectsrelated to vaccines.
Reporting Vaccine Side Effects
It’s important to report any vaccine reaction to the Vaccine Adverse Event Reporting System (VAERS). This is a registry that helps the U.S. Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) track any new or unusualside effectsrelated to vaccines.
How Long Does COVID Arm Rash Last?
COVID arm rash typically begins seven days after the vaccination and lasts about five days. However, it can last up to 21 days.
How Do You Treat COVID Arm?
COVID arm rash typically resolves with minimal treatment. Ways to get relief include:
If home treatments do not provide relief, contact a healthcare provider for prescription medications or other treatment options.
Why You Should Still Get Vaccinated
Though COVID arm rash is an unpleasant side effect that some may experience after theirimmunization, it is not a good enough reason to avoid future COVID vaccines.
COVID arm is not indicative of having a more serious reaction to futurevaccinesand actually demonstrates that the body is mounting a good immune response to the virus.
When to Contact a Healthcare Provider
COVID arm rash is a localized reaction to the COVID-19 vaccine. If a reaction worsens or causes additional symptoms, it is time tocontact a healthcare provider.
If you or someone you know is experiencing a severe allergic reaction,call 911right away. Symptoms of a severe allergic reaction include:
Summary
COVID arm rash is a reaction to the COVID-19 vaccine. It is more common after the Moderna vaccine and causes redness, itching, and swelling around the injection site.
9 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.MedlinePlus.Arm rash after COVID-19 vaccination.Wei N, Fishman M, Wattenberg D, et al.“COVID arm”: a reaction to the Moderna vaccine.JAAD Case Reports. 2021;10:92-95. doi:10.1016%2Fj.jdcr.2021.02.014Picone V, Martora F, Fabbrocini G, Marano L.“Covid arm”: abnormal side effect after Moderna COVID ‐19 vaccine.Dermatologic Therapy. 2022;35(1). doi:10.1111/dth.15197St. Luke’s.Understanding post-injection inflammation.Melbourne Vaccine Education Centre.Injection site nodules.Cedars-Sinai.What causes COVID arm?Johnston MS, Galan A, Watsky KL, Little AJ.Delayed localized hypersensitivity reactions to the Moderna COVID-19 vaccine: a case series.JAMA Dermatol. 2021;157(6):716. doi:10.1001/jamadermatol.2021.1214Centers for Disease Control and Prevention.Allergic reactions after COVID-19 vaccination.Centers for Disease Control and Prevention.How to report adverse events to VAERS.
9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.MedlinePlus.Arm rash after COVID-19 vaccination.Wei N, Fishman M, Wattenberg D, et al.“COVID arm”: a reaction to the Moderna vaccine.JAAD Case Reports. 2021;10:92-95. doi:10.1016%2Fj.jdcr.2021.02.014Picone V, Martora F, Fabbrocini G, Marano L.“Covid arm”: abnormal side effect after Moderna COVID ‐19 vaccine.Dermatologic Therapy. 2022;35(1). doi:10.1111/dth.15197St. Luke’s.Understanding post-injection inflammation.Melbourne Vaccine Education Centre.Injection site nodules.Cedars-Sinai.What causes COVID arm?Johnston MS, Galan A, Watsky KL, Little AJ.Delayed localized hypersensitivity reactions to the Moderna COVID-19 vaccine: a case series.JAMA Dermatol. 2021;157(6):716. doi:10.1001/jamadermatol.2021.1214Centers for Disease Control and Prevention.Allergic reactions after COVID-19 vaccination.Centers for Disease Control and Prevention.How to report adverse events to VAERS.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
MedlinePlus.Arm rash after COVID-19 vaccination.Wei N, Fishman M, Wattenberg D, et al.“COVID arm”: a reaction to the Moderna vaccine.JAAD Case Reports. 2021;10:92-95. doi:10.1016%2Fj.jdcr.2021.02.014Picone V, Martora F, Fabbrocini G, Marano L.“Covid arm”: abnormal side effect after Moderna COVID ‐19 vaccine.Dermatologic Therapy. 2022;35(1). doi:10.1111/dth.15197St. Luke’s.Understanding post-injection inflammation.Melbourne Vaccine Education Centre.Injection site nodules.Cedars-Sinai.What causes COVID arm?Johnston MS, Galan A, Watsky KL, Little AJ.Delayed localized hypersensitivity reactions to the Moderna COVID-19 vaccine: a case series.JAMA Dermatol. 2021;157(6):716. doi:10.1001/jamadermatol.2021.1214Centers for Disease Control and Prevention.Allergic reactions after COVID-19 vaccination.Centers for Disease Control and Prevention.How to report adverse events to VAERS.
MedlinePlus.Arm rash after COVID-19 vaccination.
Wei N, Fishman M, Wattenberg D, et al.“COVID arm”: a reaction to the Moderna vaccine.JAAD Case Reports. 2021;10:92-95. doi:10.1016%2Fj.jdcr.2021.02.014
Picone V, Martora F, Fabbrocini G, Marano L.“Covid arm”: abnormal side effect after Moderna COVID ‐19 vaccine.Dermatologic Therapy. 2022;35(1). doi:10.1111/dth.15197
St. Luke’s.Understanding post-injection inflammation.
Melbourne Vaccine Education Centre.Injection site nodules.
Cedars-Sinai.What causes COVID arm?
Johnston MS, Galan A, Watsky KL, Little AJ.Delayed localized hypersensitivity reactions to the Moderna COVID-19 vaccine: a case series.JAMA Dermatol. 2021;157(6):716. doi:10.1001/jamadermatol.2021.1214
Centers for Disease Control and Prevention.Allergic reactions after COVID-19 vaccination.
Centers for Disease Control and Prevention.How to report adverse events to VAERS.
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