The association between bariatric surgery and improvement in psoriasis: A systematic review

Summary: Abstract Body: Obesity, a risk factor for psoriasis, is linked to increased disease severity and frequency, with metabolic syndrome often compounding disease burden and reducing quality of life (QoL). Weight loss in obese patients can improve psoriasis severity, treatment responses, and metabolic health. Metabolic and bariatric surgery (MBS) has emerged as an effective intervention for weight loss. This systematic review evaluates the association between MBS and psoriasis severity. Embase, MEDLINE, and Scopus were searched until October 2024. Search terms included "psoriasis" and "bariatric surgery." Screening by two reviewers yielded 14 studies with 169 patients. The mean age was 46.8 years (range=24-56), with 74.0% female and average BMI of 43.7 kg/m2. Most patients underwent gastric bypass (75.1%), followed by sleeve gastrectomy (17.8%). Preoperative psoriasis severity was mild (15.6%, PASI<5 or BSA<3%), moderate (76.3%, PASI=5-10 or BSA=3-10%), or severe (8.2%, PASI>10 or BSA>10%). All studies documented notable weight loss (average post-MBS BMI=32.9 kg/m2, BMI reduction=8-25 kg/m2) and improved psoriasis severity: 97.2% experienced mild or resolved psoriasis, and only 2.4% reported worsening. While most patients continued psoriasis treatments post-MBS, many required downgraded therapies. Two studies noted Dermatology Life Quality Index improvements, one statistically significant. These findings suggest that MBS facilitates weight loss while improving psoriasis severity and QoL, highlighting its potential role in managing obesity-related inflammatory conditions. Psoriasis improvement may involve early reductions in proinflammatory mediators (e.g., CRP, leptin) following surgery and decreased tumor necrosis factor-α from adipose tissue after weight loss. Limitations include study heterogeneity in design and outcome reporting. Further controlled trials are necessary to validate long-term effects and establish MBS as adjunctive psoriasis therapy. Miranda K. Branyiczky¹, Megan Lowe², Ronald Vender³ 1. Michael G. DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada. 2. Queen's School of Medicine, Queen’s University, Kingston, ON, Canada. 3. Division of Dermatology, McMaster University, Hamilton, ON, Canada. Clinical Research: Interventional Research