Effects of prolonged continuous exposure of human skin to water: a reassessment.

Continuous exposure of human skin to water in small plastic cups for periods of 72 and 144 hr produced a mild, transient dermatitis in half the sites tested. The degree of dermatitis was only slightly greater at 144 than at 72 hr, and was unrelated to the pH of the water samples. Comparison of soap-pretreated to non-pretreated skin areas showed a significant tendency for the more severe dermatitis to be present on the non-pretreated skin areas at higher pH's. There was virtually no coating of hairs with waxy yellowish material (clumps of bacteria), and no lesion was produced that resembled warm-water-immersion injuries.