Such pharmacologic agents as antidepressants, belladonna alkaloids, opiates, and oral contraceptives may induce pruritus, even without producing a dermatitis.

• 药物因素如抗抑郁剂、颠茄生物碱、鸦片制剂、口服避孕药甚至在不引起皮炎的情况下都可诱发瘙痒。