In a non-limiting embodiment, there is provided a pharmaceutical composition for prevention and/or treatment of atopic dermatitis comprising an IL-31 antagonist as an active ingredient, wherein the IL-31 antagonist is repeatedly administered in equal amounts at the same dosing interval to a subject with or potentially with atopic dermatitis, at 0.1 to 1000 mg/body/1 day to 12 weeks, preferably at 0.1 to 1000 mg/body/2 weeks, 0.1 to 1000 mg/body/4 weeks, or 0.1 to 1000 mg/body/8 weeks. contracting atopic dermatitis.