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Allergy Shots: Indications, Process, and Benefits

January 22nd, 2024 | 4 min. read

By Nerissa D'Silva, MD

Allergy shots or allergen immunotherapy is a treatment that can eliminate allergy symptoms in people.

What are allergy shots? 

Allergy shots are a common and effective form of allergy immunotherapy. It is a long-term treatment used to reduce symptoms in people with different allergies.

Allergy shots are administered as regular injections over three to five years to treat allergic symptoms in people suffering from allergic conditions affecting the nose (allergic rhinitis), eyes (allergic conjunctivitis), ears (allergic otitis media), lungs (asthma), severe insect sting allergy.

Allergy shots contain a small amount of allergens. Allergens are substances that cause the immune system to overreact, causing allergic reactions. Some examples of allergens include:

  • Pollen
  • Dust mites
  • Animal dander
  • Mold spores
  • Insect venom
  • Trees, grass, weeds

Allergy shots are a cost-effective treatment that decreases sensitivity to allergens and offers long-lasting relief from allergy symptoms even after discontinuation of the treatment.


Request an appointment today to see if you are a candidate for allergy shots.

We have 9 convenient locations throughout the entire Houston area.


Why are allergy shots given?

Allergy shots can be a treatment choice if:

  • Medication cannot control the allergy symptoms, and it is not possible to avoid the allergens.
  • A person is allergic to insect stings.
  • To avoid long-term use of allergy medication.
  • To help control uncontrolled symptoms of asthma.

Allergy shots can be used to control symptoms caused by:

  • Insect stings: Insects like bees, hornets, wasps, or yellow jackets can cause allergy symptoms;
  • Seasonal allergies: Hay fever symptoms or seasonal allergies can be triggered by exposure to pollen;
  • Indoor allergens: Indoor allergens like mold, dust mites, cockroaches, and danders from dogs and cats can trigger allergic reactions.

How do allergy shots work?

Allergy shots work by injecting a diluted amount of allergen under the skin of the arm. The body then reacts to these allergens and creates antibodies to fight the invasive substances.

The allergy shots are given in gradually increasing doses to help develop immunity or tolerance to the allergens and allow the reduction of allergy symptoms.

They are administered as an injection where a small amount of allergen is injected into the skin of the arm.

The allergy shots are given in gradually increasing doses to help develop immunity or tolerance to the allergens and allow the reduction of allergy symptoms.

How effective are allergy shots?

Allergy immunotherapy is the only treatment available that changes the immune system. Allergy shots can reduce symptoms of allergies while preventing the development of newer allergies.  In children, it can prevent the progression of symptoms of asthma. 

The overall effectiveness of allergy shots will depend on the type of allergen and the duration of the treatment.

Some people experience long-term relief from allergy symptoms, while others can have a return of the allergy symptoms after discontinuing the treatment program.

The return of allergy symptoms can occur because of the following factors.

  • High levels of allergens in the environment
  • Significant exposure to non-allergic triggers like tobacco smoke
  • Missing allergens while evaluating allergic reactions
  • Inadequate allergy doses in the allergy shots

What is the process of getting allergy shots?

If you are prone to allergies, your allergist will consider your symptoms and order skin or blood tests to identify likely allergen sensitivities.

You will be given allergy shots in two phases.

The build-up phase:

The phase involves injecting a small amount of allergen into the skin of the arm. The initial allergy shot dose is given once to twice weekly for around nine months. The duration of the build-up phase depends on how often the allergy shots are given.

The duration of the build-up phase depends on how often the allergy shots are given, with the entire period lasting between three and six months.

The maintenance phase:

The maintenance phase begins once the effective dose is reached. The effective dose of an allergy shot is based on the person’s response to the buildup phase and their allergen sensitivity.

In the maintenance phase, shots are administered once a month.

The symptoms of an allergic reaction may reduce during the build-up phase, but it may take up to twelve months of maintenance to see a noticeable improvement.

Where the allergy shots are successful in reducing the symptoms, the maintenance phase can last for three to five years.

If you are curious about how allergy shots can provide lasting relief from annoying allergy symptoms, here is a comprehensive video from Dr. Nerissa D'Silva, MD, Allergist Houston ENT, Sugar Land office, you can watch. 

Who can benefit from allergy shots?

Allergy shots are best for people who suffer from:

  • Allergic rhinitis
  • Allergic asthma
  • Allergic conjunctivitis
  • Insect allergies, particularly from bees and other stinging insects
  • Eczema and other allergic skin problems

Both adults and children can have allergy shots even though they are not recommended for children below the age of five. This is because young children may have trouble cooperating or voicing any adverse reactions they may experience.

Older people with medical conditions like cardiac disease must consider allergy shots only after discussing with an allergist/immunologist.

Food allergies are not treated with allergy shots.

Before getting allergy shots, you must consult an allergist/immunologist to base your treatment decisions on the following:

  • Length of the allergy season and the severity of the symptoms.
  • Whether limiting environmental exposure or medication is helping your symptoms.
  • Whether you want to avoid long-term medications.
  • If you can commit the necessary time required for the treatment.
  • The cost of treatment for allergy shots, depending on your location and insurance coverage.

Allergy shots risks

Although allergy shots are not known to have any serious side effects, the allergens in the shots can sometimes cause adverse reactions like:

  • Local reactions: It involves swelling, redness, or irritation at the injection site and can develop within a few hours of injection.
  • Systemic reactions: Although less common, systemic reactions can be serious. People may develop nasal congestion, sneezing, or hives. In some cases, systemic reactions can involve chest tightening, throat swelling, or wheezing in people.
  • Anaphylaxis: It is a rare, life-threatening reaction to allergy shots that requires immediate medical attention. Anaphylaxis reactions can cause nausea, swelling in the throat, dizziness, and trouble breathing, the reaction often beginning within 30 minutes of the allergy injection.

The risks of allergy shots can be prevented by taking antihistamines or other medicines before your appointment. It will, however, not prevent anaphylaxis, which is why you will be prescribed an epi-pen prior to starting shot therapy. You must have this with you at every visit. The adverse reactions to allergy shots can be treated in the doctor’s office. 

Reach out to your medical provider if:

  • Your allergy symptoms remain unchanged or get worse after several months of allergy shots.
  • You have any adverse reaction at the injection site.
  • You have any concerns about the allergy treatment.
  • You need to reschedule the appointment.

Schedule an appointment with Houston ENT & Allergy.

Allergy symptoms cannot be treated overnight. To be effective, the treatment involves administering allergy shots over a period of three to five years.

Allergy shots can be a long-term and effective way of treating your annoying allergy symptoms. You may need regular allergy shots for three to five years for long-lasting relief. 

Also, the type of treatment must be supervised by a specialized physician in a facility with proper staff and equipment to identify and treat adverse reactions to the allergy injections.

Our Allergy specialists at Houston ENT & Allergy are committed to understanding your concerns and offering tailor-made treatments to treat your allergy issues. Our highly trained specialists can provide customized treatment to treat allergies and prevent any new allergy condition in you or your loved ones. 

Schedule an appointment here or call us at (281) 623-1212. We have ten convenient locations in the Houston area.

Nerissa D'Silva, MD

Nerissa D'Silva, MD, is a proud local who was raised in Sugar Land, Texas. She specializes in Allergy/Immunology and delivers outstanding, customized care in outpatient settings. She is known for her warmth and expertise in handling a variety of conditions through innovative treatments.