The present invention provides an itch suppressant containing cholecystokinin 2 receptor agonist such as a peptide having an amino acid sequence homologous with a partial amino acid sequence of at least seven C-terminal amino acids of the peptide having the amino acid sequence represented by SEQ:ID No. 1 as an active ingredient as a rapid-acting itch suppressant effective in treating skin illnesses associated with strong itch such as atopic dermatitis having few side effects. [SEQ:IDNo.1] Val-Ser-Gln-Arg-Thr-Asp-Gly-Glu-Ser-Arg-Ala-His- Leu-Gly-Ala-Leu-Leu-Ala-Arg-Tyr-Ile-Gln-Gln-Ala- Arg-Lys-Ala-Pro-Ser-Gly-Arg-Met-Ser-Ile-Val-Lys- Asn-Leu-Gln-Asn-Leu-Asp-Pro-Ser-His-Arg-Ile-Ser- Asp-Arg-Asp-Tyr(SO3H)-Met-Gly-Trp-Met-Asp-Phe-NH2
