Allergy shots, known medically as Allergen Immunotherapy, are a highly effective and disease-modifying treatment designed to provide long-term relief from persistent allergies. Unlike medications such as antihistamines and nasal sprays that only temporarily control symptoms, allergy shots work by gradually retraining your immune system to become less sensitive to specific allergens. This treatment involves a series of injections containing tiny, purified amounts of the substances you are allergic to, such as dust mites, pollen, or insect venom.

Over time, this process helps your body build a natural tolerance, leading to a significant reduction in allergy symptoms, a decreased need for daily medications, and an overall improvement in your quality of life. Administered by allergy specialists in a controlled medical environment, allergen immunotherapy is the closest thing to a cure for allergic conditions like allergic rhinitis (hay fever) and allergic asthma, offering the potential for lasting relief even after the treatment course is complete.

What is Allergen Immunotherapy (Allergy Shots)?

Allergen immunotherapy is a form of long-term medical treatment that addresses the root cause of allergies. Allergies are the result of an overactive immune system response. Your body mistakenly identifies a harmless substance, like pollen, as a threat and launches an inflammatory attack, releasing chemicals like histamine that cause the familiar symptoms of sneezing, itching, and congestion. Immunotherapy works by introducing carefully controlled, gradually increasing doses of that specific allergen into your body.

This regular exposure helps your immune system learn to tolerate the allergen rather than attack it. From a biological perspective, this process initiates several key changes:

• It stimulates the production of blocking antibodies (IgG4), which intercept the allergen before it can trigger an allergic reaction.
• It decreases the production of allergy-causing antibodies (IgE).
• It promotes the development of regulatory T-cells, a type of immune cell that helps to suppress the allergic response.

Essentially, the therapy desensitizes your body, making you less reactive to future encounters with the allergen in your natural environment. The treatment is divided into two distinct phases:

1. The Build-Up Phase: This involves receiving injections with progressively larger doses of the allergen once or twice a week. This phase typically lasts for three to six months.
2. The Maintenance Phase: Once the highest effective and tolerated dose is reached, the frequency of injections is decreased, usually to once every two to four weeks. This phase is continued for three to five years to achieve a lasting effect.

This structured, long-term approach is what allows the immune system to build a durable tolerance, providing benefits that persist long after the treatment is concluded.

When are Allergy Shots Recommended?

Allergy shots are a highly effective but significant commitment. A thorough evaluation by an allergy specialist is required to determine if you are a suitable candidate. Immunotherapy is generally recommended in the following situations:

For Specific Allergic Conditions:

• Allergic Rhinitis (Hay Fever): This is the most common reason for starting immunotherapy. It is highly effective for individuals with significant symptoms like chronic sneezing, nasal congestion, runny nose, and itching caused by allergens such as dust mites, pollens, mold spores, or animal dander.
• Allergic Asthma: For patients whose asthma is triggered by specific allergens (like dust mites or pollen), allergy shots can reduce the frequency and severity of asthma attacks, decrease the need for asthma medications, and improve overall lung function.
• Allergic Conjunctivitis: This involves chronic itchy, red, and watery eyes due to allergies and often improves significantly with immunotherapy.
• Insect Sting Allergy: Venom immunotherapy is a life-saving treatment for individuals who have had a severe, systemic reaction (anaphylaxis) to stings from insects like honeybees, wasps, or hornets. It is over 98% effective in preventing future severe reactions.

For Specific Patient Profiles:

• Inadequate Symptom Control: When standard medications, even when used correctly, fail to provide adequate relief from your allergy symptoms.
• Adverse Medication Effects: If you experience bothersome side effects from long-term use of antihistamines or nasal steroids.
• Desire to Reduce Medication Use: For individuals who wish to decrease their long-term reliance on daily allergy medications.
• Prevention of Disease Progression: In children with allergic rhinitis, immunotherapy has been shown to help prevent the development of asthma later in life (the allergic march).

It is critically important to note that allergy shots are not used for the treatment of food allergies. The only approved form of immunotherapy for food allergies is oral immunotherapy (OIT), which is a separate and distinct procedure.

Understanding the Underlying Condition: The Allergic Response

An allergic reaction is a hypersensitivity disorder of the immune system. It's a case of mistaken identity where your body's defense network overreacts to a substance that is typically harmless to most people.

The Mechanism of an Allergic Reaction:

1. Sensitization: The first time you are exposed to a potential allergen (e.g., dust mite particles), your immune system may identify it as an invader and produce a specific type of antibody called Immunoglobulin E (IgE).
2. The Allergic Cascade: These IgE antibodies attach themselves to the surface of mast cells, which are immune cells found in your skin, nose, lungs, and gut. You are now sensitized.
3. Re-exposure: The next time you encounter the same allergen, it binds to the IgE antibodies on the mast cells. This triggers the mast cells to degranulate—releasing a flood of powerful inflammatory chemicals, most notably histamine.
4. Symptoms: It is histamine and these other chemicals that cause the immediate symptoms of an allergy: blood vessels dilate (leading to congestion), nerve endings are irritated (causing itching and sneezing), and mucus production increases (leading to a runny nose).

Common Allergens in India:

The specific triggers for allergies can vary, but some of the most common inhaled allergens in the Indian context include:

• House Dust Mites: Microscopic creatures that thrive in warm, humid environments, commonly found in bedding, carpets, and upholstery. This is a primary year-round allergen.
• Pollens: From trees, grasses, and weeds. The pollen season can vary by region.
• Mold Spores: Found in damp areas, both indoors and outdoors.
• Cockroach Allergens: Proteins found in the saliva, waste, and body parts of cockroaches are a significant indoor allergen, especially in urban areas.
• Animal Dander: Tiny flecks of skin shed by animals with fur or feathers, such as cats, dogs, and birds.

Risk Factors & When to See a Doctor

While anyone can develop allergies, certain factors increase your risk, including a family history of allergies or asthma. You should consult a specialist in allergy and immunology if:

• Your allergy symptoms are chronic (lasting several months out of the year) and significantly impact your quality of life, affecting your sleep, work, or school performance.
• Over-the-counter or prescribed allergy medications are not providing adequate relief or are causing unwanted side effects.
• You are experiencing symptoms of both allergic rhinitis and asthma.
• You wish to find a long-term solution to reduce your dependence on daily medications.
• You have ever had a severe, body-wide reaction to an insect sting.

A specialist can perform definitive testing to identify your specific triggers and determine the most effective treatment plan for you.

Our Specialists

The safe and effective administration of allergen immunotherapy requires deep expertise in allergy and immunology. Our team is comprised of leading specialists in the field.

Dr. Manoj Kumar Goel

PRINCIPAL DIRECTOR & UNIT HEAD - PULMONOLOGY & SLEEP MEDICINE | Fortis Gurgaon

Dr. Prashant Saxena

SENIOR DIRECTOR & HEAD – PULMONOLOGY, PULMONOLOGY CRITICAL CARE & SLEEP MEDICINE | Fortis Vasant Kunj

Dr. Vikas Maurya

SENIOR DIRECTOR & HOD - RESPIRATORY MEDICINE & RESPIRATORY CRITICAL CARE | Fortis Shalimar Bagh

Patient Stories

“For years, my life in Delhi was dictated by my severe dust mite allergy. I would wake up every morning with uncontrollable sneezing and a completely blocked nose, and I was constantly fatigued. Antihistamines barely helped. Starting on allergy shots was the best decision I ever made. The first year required commitment, but the change has been profound. I can now breathe freely, my sleep has improved, and I've significantly reduced my need for other medications. It has truly given me my life back”.  — A. Malhotra, 34, New Delhi

“My daughter’s allergic asthma was a constant source of worry. Every change in season seemed to trigger her wheezing, and we were always on edge. Her allergist at Fortis recommended immunotherapy. The process was handled so professionally, and the team was wonderful with my child. After two years on the maintenance phase, her asthma is remarkably well-controlled. She is more active, can play sports with her friends, and we have a newfound peace of mind”.  — S. Kumar, parent of a 9-year-old, Mumbai

The Path to Immunotherapy: Diagnosis and Preparation

Before you can begin allergy shots, a precise diagnosis is essential.

1. Detailed Consultation: Your allergist will take a thorough medical history, asking detailed questions about your symptoms, their timing and triggers, and your home and work environments.
2. Allergy Testing: To confirm your specific triggers, your doctor will perform one or both of the following tests:

• Skin Prick Test (SPT): This is the most common method. A tiny drop of a purified liquid allergen is placed on your skin, usually on the forearm or back. The skin is then lightly pricked through the drop. If you are allergic, a small, raised, itchy bump (like a mosquito bite) will appear at that spot within 15-20 minutes.
• Specific IgE Blood Test: This test measures the amount of specific IgE antibodies to various allergens in your blood. It may be used if you have a skin condition that prevents skin testing or if you are taking a medication that could interfere with the results.

Personalized Treatment Formulation: Based on your test results and clinical history, the allergist will order a custom-mixed extract vial containing the specific allergens that are causing your symptoms.

The Allergy Shot Process: What to Expect During Treatment

The immunotherapy journey is a structured commitment managed closely by your healthcare team.

The Build-Up Phase

• Frequency: You will visit the clinic once or twice a week.
• Procedure: You will receive an injection in the upper arm with a very small but gradually increasing dose of your allergen extract.
• Duration: This phase continues for about three to six months, until you reach the target maintenance dose.

The Maintenance Phase

• Frequency: The time between injections is extended to every two, and then eventually every four weeks.
• Procedure: You will receive the same, consistent highest effective dose at each visit.
• Duration: This phase is the longest and most critical part of the therapy, lasting for three to five years to ensure the immune system develops a lasting tolerance.

The Protocol at Every Visit

The most important part of every allergy shot appointment is the safety protocol.

1. Injection: The nurse will administer the shot into the subcutaneous tissue of your upper arm.
2. The Mandatory 30-Minute Wait: You MUST remain in the clinic for observation for at least 30 minutes after every single injection. This is a non-negotiable safety measure. While rare, severe allergic reactions (anaphylaxis) can occur, and they typically happen within this 30-minute window. Waiting in the clinic ensures that medical staff are immediately available to treat any such reaction.

After the Shots: Long-Term Outlook and Efficacy

The benefits of allergy shots are gradual but profound.

• Timeline for Improvement: Some patients notice a decrease in their symptoms during the build-up phase, but most significant improvement occurs within the first year of the maintenance phase.
• Lasting Benefits: The primary advantage of immunotherapy is its long-term effect. Many people experience continued relief from their allergy symptoms for many years even after completing the full three to five-year course.
• Disease Modification: Immunotherapy is the only treatment that alters the natural course of the allergic disease. It can prevent the development of new allergies and, in children, reduce the risk of developing allergic asthma.

Risks & Safety Profile

Local Reactions

These are common, not dangerous, and are a sign that your immune system is responding. They include redness, swelling, or itching at the injection site. These reactions typically begin within a few hours and can be managed with a cold compress and oral antihistamines.

Systemic Reactions (Anaphylaxis)

This is a rare but potentially life-threatening allergic reaction that affects the whole body. Symptoms can include hives, swelling, tightness in the throat, difficulty breathing, dizziness, and nausea. This is precisely why the 30-minute waiting period in the clinic after every shot is mandatory. The medical staff are trained and equipped to immediately recognize and treat anaphylaxis with an injection of adrenaline (epinephrine) and other emergency measures. Adherence to this safety protocol makes the procedure extremely safe.

Myths vs Facts

Take the Next Step

If chronic allergies are controlling your life, forcing you to rely on daily medications, and preventing you from enjoying your favorite activities, allergen immunotherapy may offer the long-term solution you have been seeking. It is a commitment, but one that can fundamentally improve your health and well-being.

Our team of allergy and immunology experts can provide a comprehensive evaluation to determine if allergy shots are the right choice for you and guide you on the path toward lasting relief.

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Frequently Asked Questions

1. How long will it be before I start to feel better?

Ans. While individual responses vary, most people begin to notice a significant improvement in their symptoms within the first 6 to 12 months of starting the maintenance phase.

2. Are the injections painful?

Ans. The needle used is very fine, and the injection is given just under the skin, so the discomfort is minimal and brief, often described as less painful than a typical vaccination.

3. What happens if I miss a scheduled shot?

Ans. If you miss a shot, your allergist will have a specific protocol to adjust the dose of your next injection to ensure safety. It is important to stay as close to your schedule as possible, especially during the build-up phase.

4. Are allergy shots safe for children?

Ans. Yes, allergy shots are a safe and effective treatment for children, typically from the age of five and up. It is the only treatment proven to potentially prevent the progression of allergic rhinitis to asthma in children.

5. Is allergen immunotherapy covered by health insurance?

Ans. Coverage for allergen immunotherapy, including the allergen extracts and the administration of the shots, is common under many health insurance plans in India when deemed medically necessary by a specialist. It is always best to verify the specifics of your coverage with your provider.

6. Why is the 30-minute wait after each shot so important?

Ans. This is the most critical safety rule. Although rare, a serious systemic reaction (anaphylaxis) is most likely to occur within 30 minutes of the injection. Waiting in the clinic ensures that you are in a medically supervised environment where any such reaction can be treated immediately and effectively.

7. Can I stop taking my regular allergy medications once I start the shots?

Ans. You will likely need to continue your regular medications, especially during the build-up phase. As the immunotherapy starts to take effect during the maintenance phase, you and your doctor will work together to gradually reduce and potentially stop your other allergy medications.

8. What is the total duration of the entire treatment course?

Ans. The standard, recommended duration for allergen immunotherapy is three to five years. Completing this full course is essential for achieving the maximum, long-lasting benefit and reducing the chance of your allergies relapsing after you stop the treatment.