Allergen immunotherapy (general principles)

Introduction

It involves gradually giving controlled doses of the allergen responsible in order to reduce the sensitivity of the immune system and achieve long-term tolerance.

Indications and symptoms

Immunotherapy is intended for patients with:

• Persistent or severe allergic rhinitis
• Associated allergic conjunctivitis
• Mild to moderate allergic asthma
• Allergies to pollen, house dust mites or bee and wasp venom

👉 It aims to reduce symptoms, the need for medication and the risk of the condition worsening.

How it works

Immunotherapy acts at a deep level on the immune system:

• A reduced allergic IgE response
• Induction of tolerance mechanisms
• Less chronic inflammation
• A lasting change in the natural history of the allergy

👉 The effects are gradual but lasting, and often persist after treatment has ended.

Diagnosis first

A full allergy work-up is essential before any desensitisation:

• Precise identification of the allergen responsible
• A clear link between the allergen and the symptoms
• Appropriate allergy tests (skin and/or blood tests)
• Assessment of clinical severity

👉 Desensitisation is never started without a confirmed diagnosis.

How the treatment is given

The treatment can be given in two main ways:

• Sublingual (drops or tablets under the tongue)
• By injection (subcutaneous injections)

Treatment consists of an initial build-up phase followed by a maintenance phase, over a total of 3 to 5 years.

👉 The regimen is tailored to the patient and the allergen.

Your care

The allergy consultation is used to:

• Confirm that desensitisation is indicated
• Choose the most suitable route of administration
• Explain how treatment works and the expected benefits
• Ensure regular, safe follow-up

👉 Immunotherapy is started at the practice or in collaboration with a specialist centre.