Increased Risk of Dermatomyositis in Patients with Psoriasis: A Retrospective Cohort Study

Miao Chen,1,* Na Tian,1,* Ran Cui,1 Hua Zhang,1 Qian Wang,1 Qiang Tong,1 Zhiyong Chen,1 Yu-Hsun Wang,2 James Cheng-Chung Wei,3– 6,* Sheng-Ming Dai1,* 1Department of Rheumatology and Immunology, Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China; 2Department of Medical Research, Chung Shan Medical University Hospital, Taichung, Taiwan; 3Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Third Hospital of Shanxi Medical University, Tongji Shanxi Hospital, Taiyuan, People’s Republic of China; 4Department of Allergy, Immunology & Rheumatology, Chung Shan Medical University Hospital, Taichung, Taiwan; 5Graduate Institute of Integrated Medicine, China Medical University, Taichung, Taiwan; 6Institute of Medicine/Department of Nursing, Chung Shan Medical University, Taichung, Taiwan*These authors contributed equally to this workCorrespondence: Sheng-Ming Dai, Department of Rheumatology and Immunology, Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China, Email [email protected] James Cheng-Chung Wei, Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan, Email [email protected]: This study aimed to investigate the risk of dermatomyositis among patients with psoriasis in a large population.Patients and Methods: Individuals aged ≥ 20 years with records in the TriNetX database from January 1, 2002 to December 31, 2022 were included. Diagnoses of psoriasis, non-psoriasis, dermatomyositis, and associated comorbidities were established using the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) code. Patients who were diagnosed with dermatomyositis before the index date were excluded. Propensity score matching (PSM) was performed in a 1:1 ratio between the psoriasis group and non-psoriasis group. Kaplan–Meier curves were used to determine the cumulative incidence of dermatomyositis, and the Cox proportional hazard model was used to estimate the hazard ratio between the two groups.Results: After PSM, 301018 individuals were included in the psoriasis and non-psoriasis groups, respectively. A higher risk of dermatomyositis was identified in patients with psoriasis than in those without (HR: 2.41, 95% CI: 2.01– 2.89). This elevated risk was further confirmed in various subgroup analyses. Specifically, patients with PsA exhibited a higher incidence of dermatomyositis than those without PsA (HR, 1.73; 95% CI, 1.32– 2.28). Patients treated with interleukin-17 inhibitors (IL-17i) showed a significantly higher risk of developing dermatomyositis compared to those naïve to biological agents (HR, 5.79; 95% CI, 1.57– 21.31). In the European, Middle East, and Africa network and Asia-Pacific network, the risk of dermatomyositis in patients with psoriasis was higher than that in patients without psoriasis (HR (95% CI): 4.77 (1.40– 16.10) and 2.50 (1.33– 4.66), respectively).Conclusion: This study revealed a higher risk of dermatomyositis in patients with psoriasis than in those without. The psoriatic patients with PsA or those who had received IL-17i treatment demonstrated a significantly higher risk of developing dermatomyositis.Keywords: dermatomyositis, psoriasis, psoriatic arthritis, biological agents, incidence