To provide a parakeratosis inhibitor agent or a pore-shrinking agent comprising one or two or more compounds selected from a group consisting of benzoylaminodicarboxylic acid derivatives or benzenesulfonylaminodicarboxylic acid derivatives, as well as the salts of said derivatives as represented by general formula (2)(2) and a skin preparation for inhibiting parakeratosis for external use comprising a parakeratosis inhibitor agent and a skin preparation for shrinking pores for external use comprising a pore-shrinking agent.
