How Worried Should You Be About a Rash After Vaccination?
Arm pain after vaccination is fairly common, but some people who receive their first dose of COVID vaccine develop a red or itchy rash on the arm or sometimes all over their body. Fortunately, with the second dose, the rash goes away and doesn’t come back, at least not as badly.
It is important to understand the difference between a serious or immediate allergic reaction (which means you should not come back for a second injection) and an annoying but not serious rash sometimes referred to as the “COVID arm” or “Moderna arm”. The CDC believes that a severe allergic reaction requires the person to use adrenaline (such as an Epi-Pen) or go to a hospital. An immediate allergic reaction is a reaction that develops within 4 hours of the injection. According to the CDC:
An immediate allergic reaction occurs within 4 hours after vaccination and may include symptoms such as hives, swelling, and shortness of breath (respiratory distress). Your doctor may refer you to an allergy and immunology specialist for additional help or advice.
What does the COVID hand look like?
A less severe rash, called the COVID arm, develops more than four hours after vaccination. Sometimes they only appear after a few days or even after a week. The rash may be red, itchy, swollen, or painful.
A recent study looked at reports of skin conditions following vaccinations with Pfizer or Moderna and the results are encouraging. Of the 414 people who developed a rash after a shot and whose doctor reported the rash through a dermatological database, none developed anaphylaxis (a life-threatening allergic reaction).
The rash was temporary, and only 43% of those who got a rash after the first dose got it after the second. This means that the chances of you not getting one the second time are more than 50/50. People who get rashes both times usually have less severe rashes after the second dose.
One of the common types of skin reactions in the study was redness or itching around the injection site. Other less common reactions were a measles-like rash all over the body and “toes” caused by COVID, swelling or sores on the toes and sometimes on the fingers.
What to do if a rash develops
As always, contact your doctor if you are concerned about something happening to your body, especially if you want to rule out the possibility that the rash was caused by something other than a vaccine.
Otherwise, the CDC recommends taking antihistamines to relieve itching (if the rash is itchy) and / or pain relievers or anti-inflammatory drugs (if the rash is painful). Tylenol is a good option, NSAIDs like ibuprofen are also good options.
Even if you develop a rash, Do go back for a second dose. Tell the person giving the vaccine your reaction; they may want to give you a shot in the opposite hand.