What Are the Signs of an Allergic Reaction to a Flu Shot?

A flu shot is an immunization given to people during the winter that protects against some of the most serious or common strains of the influenza virus. Although an allergic reaction to a flu shot is rare, it can be life threatening, so it is important to recognize the signs and seek prompt medical treatment. Some of the most common signs that a person is having an allergic reaction include difficulty breathing, hives, and an accelerated heartbeat. Symptoms usually occur quickly, from a few minutes to a few hours after a person receives the shot. Although allergies to the flu vaccine are very rare, they are more likely to occur in people who are allergic to eggs, because the medicine is grown in chicken’s eggs.

Despite the fact that an allergic reaction to a flu shot is a very rare occurrence, it can be life threatening. Almost all reactions cause the person to have trouble breathing, which can eventually lead to suffocation if not treated. In other cases, an allergic reaction can be milder, with the person noticing he or she has developed hives or a skin rash after receiving the shot. In other cases, people may experience side effects from the vaccine, including body aches, mild fever, or soreness at the injection site, which are not serious and may not require medical attention. Any adverse effects that a person experiences after getting a flu shot should be reported to a physician to avoid potential serious complications.

Some people are at higher risk of experiencing an allergic reaction to a flu shot than others and may be advised against getting one. Most pediatricians do not vaccinate babies younger than six months of age, because the risk of death from an allergic reaction is higher for infants. People who have been allergic to the vaccine in past years may also not be able to get the shot, depending on the circumstances. As the vaccine is grown in chicken’s eggs, it contains trace amounts of egg protein, so people with a severe allergy to them may be more likely to have an adverse reaction to the shot. There are, however, protocols in place that allow people with egg allergies to get a flu vaccine. It’s important for patients to let their doctors know of any factors that may prevent them from being vaccinated.

As with any allergic reaction, getting prompt medical care is very important. People who suspect they are experiencing symptoms, such as wheezing or difficulty breathing, should call a doctor or get to an emergency care facility right away to be evaluated. An allergic reaction to a flu shot is treatable and completely reversible if caught early enough.