Can Allergy Shots Help With Asthma? How to Know If You Qualify

Allergic asthma is identified by positive skin prick testing (wheal 3mm or larger) or elevated specific IgE (0.35 kUA/L or higher) to aeroallergens, combined with symptoms that worsen during high-allergen periods — dusty environments, pet exposure, or high-pollen days. Blood eosinophil counts above 300 cells per microliter and fractional exhaled nitric oxide (FeNO) above 25 ppb suggest eosinophilic airway inflammation, which often overlaps with allergic asthma. Non-allergic asthma subtypes include exercise-induced bronchoconstriction (symptoms only with exercise), aspirin-exacerbated respiratory disease (worsening after NSAIDs), obesity-related asthma (without IgE elevation), and occupational asthma from chemical irritants (not allergens). A board-certified allergist can perform the full diagnostic workup to classify your asthma subtype and determine whether SCIT is appropriate.

No — SCIT should not be initiated or continued during asthma flares or when asthma is uncontrolled. AAAAI/ACAAI practice parameters specify that SCIT injections should be held when FEV1 is below 70% predicted or when asthma symptoms are poorly controlled. The reason: uncontrolled asthma is the dominant risk factor for severe systemic reactions, including the fatal reactions documented in AAAAI safety surveillance studies. Before each injection visit, your allergist or nurse should screen for asthma symptoms and, in patients with known asthma, assess peak flow or FEV1. If asthma is flaring, the injection is typically deferred until symptoms stabilize on rescue and controller medications. Once asthma returns to well-controlled status, SCIT can resume — often at a reduced dose with gradual re-escalation.

Beta-blockers (metoprolol, atenolol, carvedilol) are a relative contraindication for SCIT because they reduce the efficacy of epinephrine — the first-line emergency treatment for anaphylaxis. If a patient on beta-blockers develops a severe systemic reaction, the standard epinephrine rescue may be less effective or require higher doses. Most allergists will discuss the risk-benefit trade-off and may request cardiology consultation before initiating SCIT in a patient who cannot safely discontinue beta-blockers. ACE inhibitors are similarly listed as relative contraindications in some practice parameters due to theoretical concerns about bradykinin-mediated reactions. Inhaled corticosteroids and long-acting beta-agonists (LABAs), by contrast, are compatible with SCIT and should be continued to maintain asthma control throughout immunotherapy.

Children with allergic asthma are excellent candidates for SCIT, and may benefit more than adults from the disease-modification perspective. The PAT (Preventive Allergy Treatment) study demonstrated that children with allergic rhinitis who received SCIT were dramatically less likely to develop asthma — with an odds ratio of 2.52 for asthma prevention, sustained 7 years after stopping treatment. For children already diagnosed with allergic asthma, SCIT reduces symptom scores, medication use, and bronchial hyperreactivity. AAAAI/ACAAI practice parameters include no lower age limit for SCIT; children as young as 3 to 5 years old have received immunotherapy in clinical studies, though most allergists prefer to wait until age 5 or 6 for practical reasons. Compared to biologics — which are also approved for pediatric asthma — SCIT offers a finite 3 to 5 year course with post-treatment durability, while biologics require indefinite ongoing use.

At your first SCIT appointment for asthma, your allergist will review your asthma status — including current medications, recent symptom control, and lung function assessment. For patients with known asthma, FEV1 or peak flow is assessed before the first injection and ideally before each subsequent injection during build-up. The first injection is a very dilute, low dose of your allergen extract — usually 1,000 to 10,000 times weaker than the eventual maintenance dose. You will wait 30 minutes post-injection for observation. If no reaction occurs, you will receive the next slightly stronger dose at your next appointment, typically within one to two weeks. The build-up phase involves approximately 24 to 30 injections over 3 to 6 months; most patients with well-controlled asthma tolerate this without significant complications.

Yes — one of the most clinically significant benefits of SCIT for allergic asthma is the steroid-sparing effect. Meta-analysis from the Abramson Cochrane review shows SCIT reduces inhaled corticosteroid requirements by approximately 40% in allergic asthmatic patients, and medication score SMD of -0.53 across all medication types. This means patients who have been using high-dose ICS or requiring frequent rescue bronchodilator use may be able to step down to lower controller doses as SCIT takes effect over the first 1 to 2 years. This step-down should be managed carefully and collaboratively with both your allergist and your primary care provider or pulmonologist — abrupt discontinuation of asthma medications is never appropriate even when immunotherapy is progressing well. The goal is a supervised, evidence-based medication reduction guided by objectively measured asthma control.

For patients with allergic asthma who cannot safely receive SCIT — due to uncontrolled asthma, FEV1 persistently below 70%, beta-blocker use, or other contraindications — several alternatives exist. The HDM SLIT tablet (Odactra) is FDA-approved for house dust mite allergic rhinitis and has demonstrated asthma exacerbation reduction in the Virchow et al. JAMA 2016 trial. SLIT drops covering multiple aeroallergens are available through allergists and telehealth services. For patients with high IgE allergic asthma, omalizumab (Xolair) is FDA-approved for moderate-to-severe allergic asthma and can be used in patients whose asthma is too poorly controlled for SCIT initiation. Once omalizumab helps stabilize asthma control and FEV1, some patients subsequently become eligible for SCIT. Dupilumab addresses type 2 inflammatory asthma regardless of IgE level and is an option for both allergic and non-allergic eosinophilic subtypes.