A New Era in Food Allergy Treatment: OIT, SLIT, and Biologics Explained

Introduction

The days of passive reactive management have passed us. It is time to be proactive in food allergy care.

Food allergy management is shifting from avoidance, epinephrine, and hope to proactive interventions. Most people know about strict avoidance and emergency plans, but today, evidence-based tools like Oral Immunotherapy (OIT), Sublingual Immunotherapy (SLIT), and Omalizumab offer new hope for families burdened by food allergy.

Let’s dive into the basics of each treatment. There is no reason a patient should not have at least one of these options available—no matter where they live. Treatment should always be discussed at length with an allergist experienced in the nuance of food allergy.

Oral Immunotherapy (OIT): Desensitization Through Exposure

How it works:

• Daily ingestion of small, controlled amounts of a food allergen (e.g., peanut, milk, egg), with incremental increases over time
• Goal: raise the threshold of reactivity, so patients can tolerate accidental exposures—or eventually consume the food freely

Immune mechanism:

• Decreases allergen-specific IgE
• Increases IgG4 (blocking antibodies)
• Reduces mast cell and basophil activation
• Induces T regulatory cells

Clinical phases:

• Initial dose escalation (clinic-based, supervised)
• Build-up phase (weekly–monthly dose increases)
• Maintenance phase (daily, long-term dosing at home)

Efficacy:

• Effective for single and multiple food allergens
• FDA-approved product (Palforzia) exists for peanut OIT, though most allergists use real food
• Can lead to sustained unresponsiveness, even with reduced dosing
• Patients may aim for safety from accidental exposure or full incorporation of the food into the diet

Risks & considerations:

• GI discomfort, oral itching, and mild reactions are common
• Risk of eosinophilic esophagitis (EoE)
• Requires strong family commitment and adherence

Sublingual Immunotherapy (SLIT): Safety with Simplicity

How it works:

• Allergen placed under the tongue (usually in liquid form) for 1–2 minutes, then swallowed or spat out

Mechanism:

• Antigen presentation via oral Langerhans and dendritic cells
• Promotes immune tolerance
• Lower allergen exposure than OIT = lower systemic reaction risk

Clinical use:

• Less potent than OIT but better tolerated
• Helpful for younger children or risk-averse families
• Can be done with real foods or commercial extracts (off-label)
• Excellent safety profile, minimal systemic reactions

Limitations:

• Patients still avoid allergenic foods unless long-term SLIT has been followed by supervised challenge or used as a bridge to OIT

Omalizumab: Biologic Boost or Standalone Desensitizer

What it is:

• Omalizumab (Xolair) is a monoclonal antibody that binds free IgE, preventing activation of mast cells and basophils

FDA approval:

• In 2024, approved for IgE-mediated food allergy in patients aged 1–55 years with one or more food allergies

Use cases:

• Monotherapy: raises reactivity threshold without food dosing (but patients still avoid allergenic foods)
• Ideal for multiple food allergies, high-risk patients, or OIT-intolerant families
• Used off-label as an adjunct to OIT

Clinical evidence:

• Studies like OUtMATCH show omalizumab raises reaction thresholds
• Allows simultaneous desensitization to multiple foods

Safety:

• Generally well tolerated
• Rare risk of anaphylaxis
• Given as subcutaneous injection every 2–4 weeks, based on weight and IgE level

The Bottom Line

For patients and families exhausted by strict avoidance, now is the time to consider proactive options.

With tools like OIT, SLIT, and omalizumab, allergists can help families move beyond avoidance toward empowerment, protection, and improved quality of life. These options provide a menu of treatments that can be individualized—ensuring the right treatment is chosen for the right patient at the right time, in partnership with families.

Patients unsure where to begin can visit myimmunenetwork.com for resources.

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