“It’s challenging right now as, here in Connecticut, we are vaccinating in the age bracket in which every woman who is currently eligible for the COVID vaccine should be getting a yearly mammogram,” Dr. This has been the case for some women having mammograms, in particular, because the swollen nodes look similar to what could be an early sign of breast cancer. The fact that the enlarged lymph nodes can appear on imaging scans such as mammograms, CT scans, MRIs, and ultrasounds has raised concern among those unfamiliar with this side effect. The Pfizer-BioNTech vaccine seems to have a lower incidence, with 0.3% of patients reporting it." According to The New York Times, in Moderna’s study, "11.6% of patients reported swollen lymph nodes after the first dose, and 16% after the second dose. The swelling in the armpit was a recognized side effect in the large trials of the Moderna and Pfizer-BioNTech vaccines. If you can still feel them more than two weeks after your shot, call your doctor, she advises. They generally appear within a few days of the vaccination and you can feel them for up to 10 days-and they may be visible on imaging tests for up to a month, she says. The enlarged lymph nodes may feel like a lump and be a little tender, or you may not notice them at all, Dr. It’s your immune system reacting to the vaccine, as it should.” “The COVID-19 vaccination is given in the arm and the closest lymph nodes are the ones under your arm, so that is where the reaction is occurring,” she says. If he or she finds swollen lymph nodes, it means the body is mounting a response to an infection, explains Dr. Why does this happen? The lymphatic system is home to your immune system so when you get checked out for a cold or strep throat or flu, your doctor will feel your neck area. Swollen lymph nodes: What you need to knowĪ COVID-19 vaccine can cause enlarged lymph nodes in your armpit or near your collarbone on the side of your body where you received the injection. The Johnson & Johnson vaccine uses a different “carrier” approach, and there have not been any reports of those particular types of reactions.
Painful lump under armpit skin#
So far, swollen lymph nodes and skin reactions have only been detected in those who have received Moderna and Pfizer-BioNTech vaccines, both of which use a type of technology called mRNA (messenger RNA). “As more people get vaccinated, it’s important to allay fears and avoid unnecessary testing or treatment for conditions that should quickly resolve,” says Brita Roy, MD, MPH, an internal medicine physician and director of population health for Yale Medicine. Because information about COVID-19 changes rapidly, we encourage you to visit the websites of the Centers for Disease Control & Prevention (CDC), World Health Organization (WHO), and your state and local government for the latest information.Įven if you haven’t received a COVID-19 vaccine, you are likely aware of the common side effects associated with any vaccine, including sore arm and fatigue.īut you may not realize that COVID-19 vaccination can also cause other harmless side effects, including swollen lymph nodes or an unsightly arm rash-sometimes called “COVID arm.” Because these reactions are normal, medical experts want to get the word out to avoid any alarm for those who experience such symptoms.
Note: Information in this article was accurate at the time of original publication.