A SCCA-1 production inhibitor, comprising as an active ingredient, at least one carboxamide derivative selected from the group consisting of compounds represented by the following formula (I):wherein X is CR5 or N, R1, R4 and R5 each independently represent hydrogen, C1-C4 alkyl or a C1-C6 hydroxyalkyl group having 1-5 hydroxy groups, R2 and R3 each independently represent hydrogen, C1-C4 alkyl or a C1-C6 hydroxyalkyl group having 1-5 hydroxy groups, or each represents a group —(CH2)n—, wherein n represents an integer of 1 or 2, and may form a 5- to 6-membered ring together with the atoms to which they are bonded and with the carbonyl group, allantoin, and salts thereof.
