RESUMO
Hairless albino mice have been used to test the hypothesis of circulating mediators originating from extensive dermatitis, which might be responsible for 'false'-positive patch tests and non specific hypersensitivity. Two open patch tests with 2 or 3% phenol solution were placed on one flank at an interval of 10 days. 48 h before the second application, part of the mice received an intermediate 10% phenol solution on the opposite flank. The remaining animals served as controls. In general, intermediately treated animals showed a more pronounced reaction to the second patch test as compared to the first test, i.e., a larger granulocytic infiltrate, more extensive epithelial lesions and a elevated erythematous wall. In 6 of the 22 animals, the difference was very striking. In controls, only modest differences were observed. These findings favor the hypothesis that mediators of inflammation present in the circulation strengthen the effect of weak skin irritants.
