Changes of Cutaneous Antioxidant Enzyme Activity in Allergic Contact Dermatitis in Young and Old Individuals

Background: Reactive oxygen species, which are believed to play an important role in the aging process, are also found to be related to allergic skin diseases. Skin reactions to allergens are known to affect the antioxidant defense system such as antioxidant enzymes. Objectives: This study was conducted in order to investigate changes of the enzymatic antioxidant defense system in the lesional skin of allergic contact dermatitis (ACD) in vivoand the influence of skin aging on the changes in the enzymatic antioxidant defense system. Methods: Diphenylcyclopropenone (DPCP) application was used to induce ACD in 10 volunteers under 30 years old and in 10 over 70 years old. Antioxidant enzyme assays were performed in 5 young volunteers and 6 elderly volunteers who showed a weakly positive reaction after DPCP application. The activities of catalase, superoxide dismutase (SOD) and glutathione peroxidase (GPx) were measured in the lesional skin of ACD and in normal control skin. The differences between the two age-distinct groups were also compared and analyzed. Results: Compared with the control site, the DPCP-affected skin revealed a significantly lower catalase activity in both the young and the old groups. Reductions in cutaneous catalase activity were not different in the young and old skins. In contrast, SOD and GPx did not show any significant difference with respect to the presence of contact dermatitis or age. Conclusion: The catalase activity of human skin with ACD decreased in both young and old skins. These findings suggest that cutaneous catalase may play an important role in the pathophysiology of ACD.