Lahti A, Pylvänen V, Hannuksela M
Department of Dermatology, University of Oulu, Finland.
Contact Dermatitis. 1995 Sep;33(3):177-82. doi: 10.1111/j.1600-0536.1995.tb00541.x.
Factors affecting immediate irritant skin reactions are poorly understood. Our purpose was to study the effect of washing on reactions to benzoic acid, a well-known immediate-type irritant. 12 test subjects washed their left upper arms with a diluted dishwashing liquid 2X daily for 6 days. Benzoic acid in a dilution series was tested on both upper arms on days 0, 3 and 6. The reactions were graded visually, and the blood flow, skin color, transepidermal water loss and electrical capacitance of the test sites were measured. On days 3 and 6, the benzoic acid reactions were stronger on the washed arm than on the control arm. This was clinically visible and was associated with changes in blood flow and skin color measurements. Washing itself did not usually cause visible erythema, but transepidermal water loss increased and electrical capacitance decreased. Low concentrations of irritant substances, such as benzoic acid, may cause clinically relevant reactions in repeatedly washed skin. This should be taken into consideration in assessing product safety in the cosmetic, medical and household chemical industries, and when tests for chemical skin irritancy are designed and the results of such tests interpreted.
影响刺激性皮肤即时反应的因素目前还了解甚少。我们的目的是研究清洗对苯甲酸（一种众所周知的即时型刺激物）反应的影响。12名受试对象每天用稀释的洗碗液清洗左上臂2次，持续6天。在第0、3和6天，在双臂上测试一系列稀释度的苯甲酸。通过肉眼对反应进行分级，并测量测试部位的血流量、皮肤颜色、经表皮水分流失和电容。在第3天和第6天，清洗过的手臂上的苯甲酸反应比对照手臂上的更强。这在临床上是可见的，并且与血流量和皮肤颜色测量的变化有关。清洗本身通常不会引起可见的红斑，但经表皮水分流失增加，电容降低。低浓度的刺激性物质，如苯甲酸，可能会在反复清洗的皮肤上引起临床相关反应。在评估化妆品、医疗和家用化工行业的产品安全性时，以及在设计化学性皮肤刺激性测试并解释此类测试结果时，都应考虑到这一点。
