Allergen specific immunotherapy (ASIT) and environmental control are the only etiologic
treatments of allergic rhino-conjunctivitis, asthma and atopic dermatitis. The clinical benefit of ASIT
relies on the selection of the patients and the identification and administration of the allergen, or allergens.
Different routes of administration have been investigated, including subcutaneous, intradermal, epicutaneous, sublingual,
inhaled, or intra-lymphatic. While subcutaneous and sublingual allergen specific immunotherapy may require
from 3 to 5 years of treatment, clinical efficacy with intra-lymphatic treatment can be achieved after 3 injections. The
most severe side effect of ASIT is anaphylaxis. Novel approaches are being investigated to reduce the allergenicity of
immunotherapy vaccines, maintaining immunogenicity. Peptide immunotherapy has been directed mostly against autoimmune
diseases, but the use of synthetic peptides for ASIT is a promising field in basic science, applied immunology and
in clinical development. Short synthetic peptides bear allergen-specific CD4 T-cell epitopes which induce tolerance by
stimulating regulatory (Treg) and Th1 cells. In the present patent review, we describe new trends in allergen immunotherapy
using peptides, which, from a clinical point of view, are promising.