Skin occlusion: effect on Pityrosporum orbiculare, skin PCO2, pH, transepidermal water loss, and water content.

The effect of 8 days skin occlusion on Pityrosporum orbiculare, bacteria, skin PCO2, pH, transepidermal water loss (TEWL), and water content (WC) was studied. P. orbiculare counts increased from a baseline of 2.1 X 10(2)/cm2 to 2.3 X 10(3)/cm2 after 3 days occlusion; bacterial counts increased from 2.9 X 10(3)/cm2 to 1.8 X 10(5)/cm2 after 8 days occlusion. pH increased during occlusion from 5.6 to a maximum at day 3 of 6.7; TEWL increased to a maximum of 11.74 g m-2 h- after 3 days occlusion compared with 4.39 g m-2 h-1 before. P. orbiculare counts, pH, and TEWL were lower at 8 days than at 3 days occlusion. WC and PCO2 remained high after 8 days; relative WC was then 60.6% compared with 52.5% before occlusion; PCO2 was 63.1 mm Hg compared with 53.1 mm Hg before occlusion. The increased levels of these factors may partially explain the higher risk of infection in occluded compared with non-occluded skin.