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