Substantial research has focused on the presence of biomarkers involved in both the pathogenesis of psoriasis and its comorbidities. The identification of these biomarkers has a crucial role in establishing the diagnosis and prognosis, in understanding the physiopathological mechanism and in determining the therapeutic response. The aim of this study was to emphasize the alteration in inflammatory markers in response to systemic therapies in psoriasis. Evolution of inflammatory marker alteration was studied in 194 patients with psoriasis, aged between 7 and 87 years. Two groups were set up: the first comprised of patients treated with methotrexate (n=51), while the second comprised patients treated with biological therapy (n=143). Each group was evaluated for blood values of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and fibrinogen before and after treatment, the fluctuation of these values according to the treatment, the interrelation between inflammatory markers and inflammatory activity of the disease and the evolution of the disease after treatment. In group I, 46 out of 51 patients had elevated levels of acute phase reactants before treatment. After treatment with methotrexate 7.5 mg/week, 12 out of 46 patients had elevated blood levels of ESR and 18 out of 46 patients of CRP and fibrinogen. Before treatment with biological therapy, 138 patients out of 143 presented abnormal high range for acute phase reactants. After treatment with biological therapy, 18 patients out of 138 had elevated blood levels of ESR and 37 patients out of 138 had elevated CRP and fibrinogen. A favorable evolution was noted in 98 patients out of 138. It was concluded that the systemic treatment with both methotrexate and biological therapy showed a marked decline in the patients with abnormal values of CRP, ESR and fibrinogen, indirectly showing a decline in the inflammatory activity of psoriasis.