C‐reactive protein in psoriasis: a review of the literature

Abstract A great deal of research has addressed the elevation of C‐reactive protein (CRP) among psoriatic patients and the role of this marker in assessment of disease severity and progression. However, there are some discrepancies in this area. We sought to figure out the relationship between CRP values and disease severity as well as the changes in marker levels after treatment through an extensive literature review. Comparison between CRP levels in psoriatic patients and those in healthy or non‐psoriatic individuals was also another focus of this review. A thorough search in Pubmed and Embase was conducted for articles investigating different aspects of CRP measurement in patients with psoriasis. Overall, 32 articles were found to meet our inclusion criteria. Of 28 studies comparing the CRP values in psoriatic patients with those of controls, 24 found a statistically significant difference. In addition, 12 out of 16 papers examining the association between disease severity and CRP values noted significant results. With regard to CRP changes over the course of a treatment, all 15 studies addressing this issue revealed a significant decrease in marker levels. In conclusion, high CRP levels only for moderate and severe forms of disease might be inferred from the literature and there is no sufficient evidence suggesting a similar association for mild disease as well. Moreover, CRP may serve interchangeably with Psoriasis Area and Severity Index ( PASI ) as a measure of disease severity in the case of untreated psoriatic patients who do not have disease related arthritis. For other patients, however, a careful clinical examination and PASI calculation still remain the mainstay of severity assessment.