PROBLEM TO BE SOLVED: To provide a medicine for searching a substance that suppresses a delayed-phase allergic reaction, and particularly for treating a disease caused by a delayed-phase allergic reaction such as nasal obstruction or reducing the symptoms thereof. A delayed-phase allergic reaction inhibitor containing ibuprofen or a salt thereof or methylephedrine or a salt thereof as an active ingredient. [Selection diagram] Fig. 3【課題】遅発相アレルギー反応を抑制する物質を探索し、特に鼻閉等の遅発相アレルギー反応に起因する疾患を治療ないしその症状を軽減する医薬を提供すること。【解決手段】イブプロフェン若しくはその塩又はメチルエフェドリン若しくはその塩を有効成分として含有する遅発相アレルギー反応抑制剤。【選択図】図３
