Dermatitis patients, and complete response to the severe cases that are judged to be highly intractable not only effective and safe, the external preparation of conventional against atopic dermatitis in particular, face, object of the present invention, the neck application to the site of disease and the like are possible, and further, to provide a dermatitis treatment agent with excellent efficacy and safety that can be applied with confidence cases skin is sensitive, even women and children. In addition, it is an object of a needle of skin of skin, improvement of wrinkles, moisturizing effect, and to provide an effective external preparation for skin care cosmetics that are also hair growth effect. Skin external preparation composition comprising, as an active ingredient, C-type natriuretic peptide or B-type natriuretic peptide (CNP) and (BNP), in particular, resolution means is a skin quality improving agent or dermatitis treatment agent.本発明の課題は、皮膚炎患者、特にアトピー性皮膚炎に対して有効かつ安全であるばかりでなく、従来の外用剤では非常に難治性と判断される重症例に著効し、顔面、首等の疾患部位への塗布が可能であり、更には、皮膚が敏感な症例、小児や女性にも安心して塗布できる有効性と安全性の優れた皮膚炎治療剤を提供する。また、皮膚の肌のハリ、しわの改善、保湿効果を有し、育毛効果もあるスキンケア化粧料に有効な外用剤を提供することにある。解決手段は、C型ナトリウム利尿ペプチド(CNP)またはB型ナトリウム利尿ペプチド(BNP)を有効成分とする皮膚外用剤組成物、特に、皮膚炎治療剤または肌質改善剤である。
