発はっ赤せき薬やくはっせきやくMeanings1nounrubefacientrare termRare medical term for a substance that causes skin redness; the synonym 引赤薬 is more commonly used.See also: 引赤薬発はっ赤せき薬やくは、皮ひ膚ふに塗ぬると血けっ管かんを拡かく張ちょうさせて赤あかみを起おこす。A rubefacient, when applied to the skin, dilates blood vessels and causes redness.