title: Optimal patch application time in the evaluation of skin irritation.
abstract: We investigated the optimum application for evaluating skin irritation response by using samples of irritants commonly used as additives in cosmetics and other common household products. We studied 47 volunteers (16 men and 31 women). We selected three types of surfactant, one moisturizer, one anti-infective agent and one oil solution. Using Finn chambers on Scanpor tape, we performed the patch test. A total of 0.015 mL of each sample was applied to the Finn chamber. For liquids, circular filter paper was soaked in 0.015 mL of the sample. Samples were placed on the upper back of participants, and closed for 4, 24 or 48 h. A patch application time of 24 h is sufficient to detect primary skin irritation from irritants in cosmetics and other common household products. In addition, we found that skin irritation reactions were strongest at 24 h after patch removal and that the reaction tended to be weaker at 48 h after patch removal. Patch testing to evaluate irritants should be performed by means of a 24-h patch test with a follow-up reading at 24 h after patch removal. An application time of 24 h places less of a burden on patients than a 48-h patch test.
authors: First Department of Dermatology, Toho University School of Medicine, Tokyo, Japan. derma1st@med.toho-u.ac.jp
authors: Hiromi
authors: H
authors: Kanto
authors: Kumiko
authors: K
authors: Washizaki
authors: Masatoshi
authors: M
authors: Ito
authors: Kayoko
authors: K
authors: Matsunaga
authors: Hirohiko
authors: H
authors: Akamatsu
authors: Keiichi
authors: K
authors: Kawai
authors: Norito
authors: N
authors: Katoh
authors: Masaru
authors: M
authors: Natsuaki
authors: Isao
authors: I
authors: Yoshimura
authors: Hajime
authors: H
authors: Kojima
authors: Yuko
authors: Y
authors: Okamoto
authors: Minehiro
authors: M
authors: Okuda
authors: Hirofumi
authors: H
authors: Kuwahara
authors: Mariko
authors: M
authors: Sugiyama
authors: Shigemi
authors: S
authors: Kinoshita
authors: Fukuyoshi
authors: F
authors: Mori
mesh_terms: D000328:Adult; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D010328:Patch Tests / Q000379:methods*; D012015:Reference Standards; D023422:Skin Irritancy Tests / Q000379:methods*; D013997:Time Factors; D055815:Young Adult