What are the injections called that people get to treat allergies, specifically immunotherapy (Allergy Shots)?

From the Guidelines

Allergy shots, also known as allergen immunotherapy or subcutaneous immunotherapy (SCIT), are injections that people receive to treat allergies. These shots contain tiny amounts of the substances that trigger allergic reactions (allergens), such as pollen, dust mites, pet dander, or insect venom. According to the most recent study 1, allergen immunotherapy is a type of treatment used to reduce allergy symptoms and improve quality of life.

The treatment typically involves two phases: a build-up phase with injections 1-2 times per week for 3-6 months, gradually increasing the allergen dose, followed by a maintenance phase with injections every 2-4 weeks for 3-5 years. The goal is to desensitize the immune system by gradually exposing it to increasing amounts of allergens, helping it develop tolerance rather than triggering allergic symptoms.

As stated in the study 1, both SCIT (shots) and SLIT (tablets and drops) are considered safe and effective; however, there are differences in associated risks and benefits, including efficacy, convenience, and cost. Patients should discuss the available options with their healthcare provider.

It's worth noting that, as mentioned in the study 1, the typical duration of treatment for either form of immunotherapy is several years, typically 3 to 5 years, and demonstration of IgE-mediated allergy based on history and confirmed by specific allergy testing (skin or in vitro) is a prerequisite for all forms of immunotherapy, both SLIT and SCIT.

Some key points to consider when undergoing allergy shots include:

• The treatment is particularly effective for environmental allergies, insect sting allergies, and some forms of asthma, though they're not typically used for food allergies.
• Patients should expect to commit to the full treatment course for maximum effectiveness and should be aware that initial improvement may take 6-12 months to become noticeable.
• The treatment works by shifting the immune response from an allergic reaction (dominated by IgE antibodies) to a more normal immune response (with IgG antibodies).
• As reported in the study 1, allergen immunotherapy in inhalant allergy is a safe method of treatment, with most systemic reactions being late and including dyspnoea, rhinorrhoea, fever, fatigue, and urticaria.

From the Research

Allergy Injections

The injections used to treat allergies are called allergen immunotherapy, also known as allergy vaccine therapy 2. This treatment involves the administration of gradually increasing quantities of specific allergens to patients with IgE-mediated conditions until a dose is reached that is effective in reducing disease severity from natural exposure.

Types of Allergen Immunotherapy

There are two main types of allergen immunotherapy:

• Subcutaneous immunotherapy (SCIT): involves injecting allergens into the skin 3, 4, 5
• Sublingual immunotherapy (SLIT): involves placing allergens under the tongue 3, 4, 5

Effectiveness of Allergen Immunotherapy

Allergen immunotherapy has been shown to be effective in the treatment of:

• Stinging-insect hypersensitivity 2
• Allergic rhinitis or conjunctivitis 2, 3, 4, 5
• Allergic asthma 2, 3, 5 However, it is not effective in the treatment of:
• Atopic dermatitis 2
• Urticaria 2
• Headaches 2
• Food or antibiotic allergies 2

Administration and Safety

Safe administration of allergen immunotherapy requires:

• Immediate availability of a health care professional capable of recognizing and treating anaphylaxis 2
• An observation period of 20 to 30 minutes after injection 2
• Patients should not be taking beta-adrenergic blocking agents when receiving immunotherapy 2