“…Thus, following the analysis of the included studies, most papers delineated a significant alteration of the redox balance, with a significant decrease in antioxidant enzymes and antioxidant markers and an increase in pro-oxidant molecules in psoriasis. A conundrum of research endeavors which collected venous blood samples from individuals suffering from psoriasis with variable duration of the disease detected low levels of total antioxidant status [ 37 , 38 , 46 , 47 , 51 , 54 , 63 , 64 ] and alterations in enzymes involved in decreasing free oxygen radicals concentrations, i.e., catalase [ 21 , 22 , 39 , 40 , 47 , 54 , 61 ], superoxide dismutase [ 39 , 47 , 54 , 61 , 63 , 65 ], paraoxonase-1 [ 15 , 23 , 39 , 43 , 50 , 51 ] and glutathione peroxidase [ 25 , 63 ]. Several studies with contradictory results were also present, highlighting that in psoriasis a significant elevation in the levels of the aforementioned antioxidant molecules can also occur [ 14 , 25 , 61 , 65 ].…”