Corticosteroid injections are a last resort for treating seasonal allergies. They’re prescribed when other treatments, such as antihistamines and decongestants, don’t work.

Allergies occur when your immune system recognizes a foreign substance as a threat. These foreign substances are called allergens, and they don’t trigger a reaction in everyone.

When you come into contact with these allergens, your immune system goes on the defensive, causing symptoms such as sneezing, nasal congestion, and itchy or watery eyes.

Seasonal allergies, also known as hay fever or allergic rhinitis, have no cure. However, there are a number of effective medical treatments. These include:

Corticosteroids, a type of steroid hormone, may be prescribed if the above treatments aren’t working and your allergy symptoms are interfering with your everyday activities. They work by suppressing inflammation caused by an overly reactive immune system.

Corticosteroids are available as nasal sprays, topical creams, pills, and long-lasting injections. They are not the same as immunotherapy injections, which don’t include steroids.

Read on to find out more about the benefits, costs, and potential side effects of corticosteroid shots for allergies.

Duration may be one of the best benefits of corticosteroid injections for allergies. One injection can last between 3 weeks and 3 months. During this time, the corticosteroid is slowly released into your body.

A long-lasting shot may mean that you only require one shot per allergy season. However, long-lasting shots come with risks. In particular, there’s no way to remove the steroid from your body if you experience side effects.

There are limited studies examining the effectiveness of steroid shots over time, as the risk of serious side effects increases with repeated use.

The cost of an allergy steroid shot depends on several factors, including:

  • the type of corticosteroid
  • the concentration
  • the quantity

For example, kenalog-40 (triamcinolone acetonide) can range in price from approximately $15 to $100 per injection. That doesn’t include the cost of administration by your doctor.

Your insurance plan may not cover steroid shots for allergies, as they’re not considered a first-line treatment. Contact your insurance provider to find out what your plan covers.

Steroid shots for allergies may relieve allergy symptoms. However, they can also trigger short- and long-term side effects.

Short-term side effects

Short-term side effects of corticosteroid shots can range from mild to severe. They can include:

Long-term side effects

Taking steroid shots for a prolonged period of time increases the risk of more serious side effects. Long-term side effects can include:

Side effects for people with chronic conditions

Since corticosteroid shots suppress inflammation and your immune response, they can hide common signs of illness and infection, putting you at risk.

People with certain chronic conditions may be at an increased risk for serious side effects as the result of a steroid shot for allergies. Be sure to let your doctor or allergist know if you have (or have had) any of the following conditions:

Precautions

Tell your doctor if you’re taking medication, vitamins, or nutritional supplements. Steroid shots are not considered safe for children and women who are pregnant, trying to become pregnant, or breastfeeding.

Your doctor can help you find the best treatment for your allergies based on your current health, medical history, and allergy symptoms.

Talk with your doctor or allergist about all the available allergy treatments. They can help you weigh the effectiveness, cost, and side effects of each treatment to determine which one is the most appropriate for you.

Allergy immunotherapy

Allergy immunotherapy injections, often referred to as “allergy shots,” are not the same as corticosteroid injections.

Immunotherapy injections don’t contain steroids. They’re administered over a period of several years. Each shot contains a tiny amount of an allergen.

This amount is gradually increased over the first 3 to 6 months and then maintained with shots at a lesser frequency for 3 to 5 years.

While allergy shots can eventually prevent and lessen allergy symptoms, they don’t usually work right away. Sometimes, it can take a year or longer before they provide relief from symptoms.

Nasal corticosteroids

Nasal corticosteroids are another common treatment for seasonal allergies. While these drugs contain steroids, they carry much less risk than steroid shots and pills because they target a specific area of the body.

Nasal corticosteroids suppress the allergic response and relieve many allergy symptoms, including nasal congestion and a runny nose.

Over-the-counter medications

Antihistamines, decongestants, and combination drugs are also effective at treating symptoms of hay fever.

Antihistamines block a protein called histamine, which is released when your immune system encounters an allergen.

Decongestants help to relieve nasal congestion. Some allergy medications include both an antihistamine and a decongestant.

Mast cell stabilizers

Mast cell stabilizers are drugs used to prevent allergy symptoms, such as itchy eyes and a runny nose. Eye drops and nasal sprays containing mast cell stabilizers prevent the release of histamine where they are applied.

Other treatments

Other treatments for allergies include lifestyle changes and alternative therapies, such as:

  • avoiding allergens
  • allergy-proofing your home and workspace
  • nasal rinses

Long-lasting steroid shots can help relieve symptoms of seasonal allergies. However, they carry a serious risk of side effects, especially if you take them in the long term.

In general, they’re considered a last resort for treating severe allergies, particularly when other treatments don’t work.