Lindgren S, Groth O, Molin L
Contact Dermatitis. 1976 Aug;2(4):212-7. doi: 10.1111/j.1600-0536.1976.tb03029.x.
Three patients treated daily with vitamin A acid cream experienced after one week, seven weeks and 14 weeks respectively sudden redness and itching at the treated sites. Patch testing with the cream (containing 0.05% vitamin A acid) and with vitamin A acid 0.05% in absolute alcohol produced strongly positive reactions in the patients but only slight erythema in some of the controls. Since patch testing with vitamin A acid 0.005% in absolute alcohol elicited no response in controls but positive reactions in the three patients, it is probable that these latter reactions were due to contact allergy. Histologically the test reaction showed intact epidermis and dense dermal infiltration by mononuclear cells, and thus resembled a response of the tuberculin type.
三名每日使用维甲酸乳膏治疗的患者分别在一周、七周和十四周后，治疗部位突然出现发红和瘙痒。用该乳膏（含0.05%维甲酸）及0.05%维甲酸的无水乙醇溶液进行斑贴试验，患者出现强阳性反应，而部分对照者仅出现轻微红斑。由于用0.005%维甲酸的无水乙醇溶液进行斑贴试验时，对照者无反应，而三名患者出现阳性反应，因此这些反应很可能是由于接触性过敏所致。组织学检查显示，试验反应的表皮完整，真皮有密集的单核细胞浸润，因此类似于结核菌素型反应。
