The present invention relates to a pharmaceutical composition containing a peptide and a pharmaceutically acceptable carrier or diluent wherein the peptide has a length of 8 to 50 amino acids, at least three preferably consecutive amino acids of the peptide are identical to at least three amino acids which appear in close vicinity on the molecular surface of an allergenic protein, and said at least three amino acids are solvent-exposed amino acids in the allergenic protein. The invention also concerns a method for the preparation of the pharmaceutical composition.