Compared Burden of Psoriasis, Atopic Dermatitis, Hidradenitis Suppurativa, and Chronic Urticaria: Baseline Characteristics of the Patients Included in the OMCCI Cohort - A French, Prospective Multicenter Study of Chronic Inflammatory Dermatoses

Introduction: Chronic inflammatory dermatoses (CIDs) can significantly affect patients' lives. The Observatory of Chronic Inflammatory Skin Diseases (OMCCI) cohort was initiated to quantify the impact and disease evolution of four CID over 4 years' follow-up; at least 1,000 patients per CID are planned to be enrolled. The objective of this study was to present baseline characteristics of patients included in the OMCCI cohort between December 2020 and September 2022.

Methods: This French, prospective, multicenter registry included adult patients treated in daily practice for moderate-to-severe psoriasis (PS), atopic dermatitis (AD), hidradenitis suppurativa (HS), or chronic urticaria (CU) starting or modifying a systemic treatment. At the inclusion visit and then every 6 months during 4 years, patient-reported outcomes and data on these diseases and their treatments are recorded.

Results: A total of 2,058 patients from 24 centers were included: 1,137 PS, 413 AD, 301 HS, and 207 CU. Of these, 1,950 patients started or changed systemic treatment, and 108 reduced the dose of existing systemic treatment. Disease impact was qualified as debilitating by 80.1% (PS), 90.5% (AD), 90.5% (HS), and 89.4% (CU), affecting daily, family, and professional life. According to the SF-12 Survey, the impact of all four diseases was borderline pathological for physical health and severe for mental health. At inclusion, 20.4% of patients were receiving a conventional systemic or biologic treatment. After the first visit, this percentage raised to 83.3%. During the 6 months preceding study inclusion, 17.7% (PS), 27.9% (AD), 43.1% (HS), and 43.6% (CU) of patients missed work due to their illness, and 26.3% of patients with HS had been admitted to hospital (vs. 8.1%, 5.8%, and 13% of patients with PS, AD, or CU, respectively).

Conclusion: These CIDs (especially HS) had a major impact on all aspects of patients' quality of life. The low baseline use of systemic drugs and the high burden of these CIDs suggest that these agents are underused. Long-term and dynamic evaluation of the changes brought by the initiation or optimization of these treatments on the evolution of patients' lives will be studied prospectively during the 4-year follow-up of the OMCCI.