Allergy shots, also known as allergen immunotherapy, are a long-term treatment designed to reduce or stop allergy symptoms. This treatment involves a series of injections, typically administered over three to five years, containing small amounts of the specific substances that trigger a person’s allergic reactions. The purpose is to gradually train the immune system to build tolerance to these allergens, thereby lessening the body’s allergic response over time.
Understanding Post-Shot Fatigue
Some individuals may experience tiredness or fatigue after receiving an allergy shot. This occurs because the immune system becomes activated in response to the injected allergens. The body perceives these introduced allergens as something it needs to process and adapt to. This immune response requires energy, which can lead to a temporary sluggishness or exhaustion.
The immune system can release signaling molecules known as cytokines. Certain cytokines induce systemic effects like malaise and fatigue, similar to a mild infection. This indicates the body is actively working to build tolerance and modify its allergic reaction. For most people, any associated tiredness is mild and resolves within 24 hours.
Other Common Reactions
Beyond fatigue, other mild reactions are commonly experienced after allergy shots. The most frequent are localized responses at the injection site. These include redness, swelling, or itching at the injection site. These local reactions appear within hours and subside quickly.
Sometimes, individuals may experience mild systemic reactions, which affect parts of the body beyond the injection site. Symptoms may include sneezing, a runny nose, itchy eyes, or hives. These reactions are mild and temporary, resolving within a day. Healthcare providers monitor patients for at least 30 minutes after each shot to address any immediate reactions.
Managing Side Effects
Individuals can take several steps to manage side effects, including fatigue, after an allergy shot. Resting adequately before and after the injection helps the body cope with immune system activity. Staying hydrated also supports the body’s processes.
For localized swelling or discomfort at the injection site, applying a cold compress can provide relief. If advised by a healthcare provider, taking over-the-counter antihistamines before the shot may help reduce the risk of reactions. It is important to discuss any persistent or worsening symptoms with a healthcare provider, especially if fatigue lasts for several days or if severe reactions occur.