Better selection of responders based on an endotype-driven strategy is desired to increase both efficacy and safety.

High-quality studies are needed to answer questions regarding optimal dosing strategies, disease-modifying potential, and cost-effectiveness over the standard of care.

AIT achieves substantial clinical results in patients with AR by improving nasal and ocular symptoms and reducing medication need, improving quality of life, preventing progression of AR to asthma, and reducing new sensitizations.

SLIT and SCIT can be used in patients with mild and moderate asthma associated with allergic rhinoconjunctivitis provided that asthma is controlled by pharmacotherapy.

A measurable clinical benefit on asthma symptoms and a steroid-sparing effect is expected.

AIT cannot be presently recommended as single therapy when asthma is the sole manifestation of respiratory allergy.

Medical conditions that reduce the patient’s ability to survive the systemic allergic reaction or that make the resultant treatment a relative contraindication for AIT must be identified. Examples include severe asthma uncontrolled by pharmacotherapy and significant cardiovascular disease.

There is no contraindication for AIT in patients with respiratory allergic diseases (allergic rhinoconjunctivitis and mild allergic asthma) associated with AD.

AIT might have positive effects in selected sensitized patients with AD; the best evidence is available for HDM AIT.

Patients with a positive IgE test response and corresponding history of eczema triggered by a clearly defined allergen are potential candidates for AIT in the setting of AD.

For food allergy, an EAACI systematic review of the literature highlighted a large heterogeneity in the protocols used by different research groups in terms of preparation of food allergens, updosing, maintenance dose, and OFC procedure; therefore there is no single established protocol that has been shown to be both effective and safe in large multicenter studies.

Currently, there is agreement that although immunotherapy to foods is an important area of research, it is not yet ready for clinical practice.

Some risk factors for SCIT-induced severe SRs have been identified, but none have been clearly established for SLIT.

Both SLIT and SCIT have acceptable safety profiles if administered under the appropriate circumstances. SLIT’s more favorable safety profile allows for administration outside of a medically supervised setting, whereas SCIT is recommended only in a medically supervised setting with appropriate staff and equipment to identify and immediately treat anaphylaxis.

Consistent use of the uniform classification systems for grading AIT-related (SLIT and SCIT) SRs and LRs both in clinical trials and surveillance studies will allow better comparisons and best practices for all AIT treatments.