In vivo assessment of iron and ascorbic acid in psoriatic dermis.

Reactive oxygen species play an important role in inflammatory skin diseases such as psoriasis. Reactive oxygen species synthesis is catalysed by iron and some species are scavenged by ascorbic acid. The aim of this work was to assess iron and ascorbic acid in uninvolved and involved psoriatic dermis and to compare the corresponding concentrations in the dermis of healthy subjects. Microdialysis associated with atomic absorption spectrometry and gas chromatography-mass spectrometry was used to assess iron and ascorbic acid, respectively. Seven psoriatic patients and five healthy volunteers were studied. Iron concentrations in the involved (57.1 +/- 19.3 microg/l) and uninvolved (49.7 +/- 27.1 microgl/l) psoriatic dermis were higher than the corresponding value determined in the dermis of healthy subjects (21.8 +/- 2.4 microg/l) (p<0.05). Ascorbic acid in involved (47.3 +/- 8.2 microg/ml) and uninvolved (42.0 +/- 14.0 microg/ml) psoriatic dermis was statistically lower than that found in healthy dermis (176.8 +/- 29.0 microg/ml) (p<0.05). These results demonstrate that psoriatic patients exhibit high iron and low ascorbic acid concentrations in the dermis, but there were no significant differences between involved and uninvolved skin.