Allergy Shots vs SLIT Tablets for Asthma: A Complete Comparison Guide

If you're tired of relying on daily inhalers to manage your asthma symptoms, you're not alone. Millions of people with allergic asthma face this challenge. But there's a game-changing option that treats the root cause of allergies-instead of just masking symptoms. It's called Allergen Immunotherapy a treatment that trains your immune system to stop overreacting to allergens, and today we're breaking down the two main choices: allergy shots versus sublingual tablets.

What is Allergen Immunotherapy?

Allergen immunotherapy (AIT) is the only treatment that actually changes how your immune system responds to allergens. Unlike inhalers or pills that only control symptoms temporarily, AIT works by slowly exposing your body to tiny amounts of the things you're allergic to. Over time, this helps your immune system build tolerance. Think of it like a vaccine for allergies. The European Academy of Allergy and Clinical Immunology (EAACI) confirms this approach targets the underlying cause of allergic asthma, not just the symptoms. Studies show it can reduce medication use, prevent asthma attacks, and even lower the risk of developing asthma in people with seasonal allergies.

Allergy Shots: How They Work

Allergy shots, also known as Subcutaneous Immunotherapy (SCIT) a treatment involving regular injections of allergens under the skin, have been around since 1911. Here's how they work: First, your allergist gives you small doses of the allergen through injections. You start with weekly shots for 3-6 months (the build-up phase). Then you switch to monthly maintenance shots for 3-5 years. Each visit requires you to stay at the clinic for 30 minutes after the injection to watch for reactions. While this seems inconvenient, SCIT is highly effective for multiple allergens. For example, if you're allergic to both pollen and dust mites, one shot can cover both. A 1999 study by Dr. Mungan showed SCIT significantly reduced asthma symptoms and medication use in patients with dust mite allergies. The downside? It requires consistent clinic visits and carries a small risk of serious reactions like anaphylaxis.

SLIT Tablets: The Sublingual Alternative

Sublingual Immunotherapy (SLIT) a treatment using tablets or drops placed under the tongue is the newer, more convenient option. Instead of shots, you place a tablet under your tongue for 2 minutes before swallowing. After your first dose is supervised at the clinic, you can take it at home daily. SLIT is especially effective for house dust mite allergies. For example, ACARIZAX tablets-standardized to 6 SQ-HDM units-have been shown to reduce inhaled corticosteroid use by 42% in patients with dust mite-triggered asthma (Asperti, 2024). This means less reliance on daily steroids. SLIT has a much better safety profile too. Most side effects are mild, like an itchy mouth or throat, and they usually go away after a few weeks. Systemic reactions (like trouble breathing) are extremely rare. The trade-off? SLIT only works for one allergen at a time, and you must remember to take it every single day.

Shots vs Tablets: Direct Comparison

Who Should Choose Shots?

Allergy shots might be right for you if:

• You're allergic to multiple allergens (like pollen, dust mites, and pet dander)
• You can commit to regular clinic visits (about 50 total over 3 years)
• Your asthma is moderate and well-controlled (GINA steps 1-3)
• You prefer a treatment that doesn't require daily self-administration

For example, if you live in a place with high pollen counts and dust mites year-round, SCIT can target all these triggers at once. However, if you have severe asthma (GINA steps 4-5) or can't make consistent clinic visits, shots may not be the best fit.

Who Should Choose Tablets?

SLIT tablets could be ideal for you if:

• Your main allergy trigger is house dust mites (common in homes worldwide)
• You want to avoid needles and clinic visits
• You can remember to take a tablet daily (after the first supervised dose)
• Your asthma is mild to moderate (GINA steps 1-3)

Real-world data from a 2024 study tracking 14,614 patients shows SLIT users had 20% fewer lower respiratory infections needing antibiotics after treatment ended. This means fewer sick days and hospital visits. Brands like ACARIZAX (for dust mites) and GRAZAX (for grass pollen) are approved in Europe and widely used. If you're worried about side effects, SLIT is generally safer than shots-most reactions are just mild mouth itching that fades quickly.

Real-World Results You Can Trust

Don't just take our word for it. A landmark 2024 study by Dr. Asperti analyzed real-world data from over 14,000 patients. Those on any form of allergen immunotherapy (shots or tablets) had:

• 42% reduction in inhaled corticosteroid use for dust mite allergies
• 20% fewer lower respiratory infections requiring antibiotics after treatment ended
• Sustained symptom relief for up to 9 years after stopping treatment

This isn't just about feeling better-it's about long-term health benefits. For example, a child with allergic rhinitis who starts AIT may have a 90% lower risk of developing asthma later in life (Batard, 2025). The key? Both options work best when your allergist confirms you have IgE-mediated allergies (not just any asthma). Skin prick tests or blood tests are essential first steps.

What's Next for You?

Here's what to do next:

1. Ask your doctor for allergy testing. Skin prick tests or specific IgE blood tests will identify your exact triggers.
2. If dust mites are your main problem, SLIT tablets like ACARIZAX are a top choice. They're convenient and effective.
3. If you have multiple allergies or prefer clinic-based treatment, discuss SCIT with your allergist.
4. Start treatment early. AIT works best when started before symptoms become severe.

Remember: AIT isn't a quick fix. It takes 3-5 years of consistent treatment for full benefits. But for many people, the payoff is worth it-fewer asthma attacks, less medication, and better quality of life long after treatment ends.