Treatment Options for Allergen Immunotherapy

Allergen immunotherapy (AIT) is a type of treatment used to reduce allergy symptoms and improve quality of life. AIT has been shown to be safe and effective for treating allergic rhinitis (hay fever). For allergens that are inhaled, AIT is usually administered using one of two methods:

  • Subcutaneous immunotherapy (SCIT), which involves placing allergens under the skin with a needle
  • Sublingual immunotherapy (SLIT), which involves using drops or tablets placed under the tongue

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. Please see below for a more detailed comparison.

Comparison of SCIT and SLIT for Allergic Rhinitis


SCIT (shots)—Higher risk of local and systemic (whole body) reactions relative to SLIT

SLIT (tablets)—Mild local and rare systemic reactions

SLIT (drops)—Mild local and rare systemic reactions


SCIT (shots)—Approved by the U.S. Food and Drug Administration (FDA)

SLIT (tablets)—Approved by the U.S. FDA

SLIT (drops)—Not approved by the U.S. FDA and is considered “off-label”


SCIT (shots)—Given in a doctor’s office during regular clinic visits

SLIT (tablets)—Given in a doctor’s office during first dose, at home after the first dose

SLIT (drops)—Given in a doctor’s office during first dose, at home after the first dose

Number of Allergens Delivered

SCIT (shots)—Can be tailored to match all positive allergy tests

SLIT (tablets)—Limited to certain allergens like grass, house dust mites (HDM), or ragweed

SLIT (drops)—Can include one to 10 allergens, but there’s some debate and evidence is limited


SCIT (shots)—Works better compared to SLIT

SLIT (tablets)—Not as effective as SCIT

SLIT (drops)—Not as effective as SCIT


SCIT (shots)—Insurance covered

SLIT (tablets)—Insurance covered

SLIT (drops)—Usually out of pocket


Gurgel RK, Baroody, FM, Damask, CC, et al. Clinical Practice Guideline: Immunotherapy for Inhalant Allergy. Otolaryngology–Head and Neck Surgery. 2024;170(S1):S1-S42.

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The information on is provided solely for educational purposes and does not represent medical advice, nor is it a substitute for seeking professional medical care.