Background: Tonsillectomy has been suggested as an intervention to resolve psoriasis. Objective: This study aimed to investigate the subsequent risk of psoriasis in patients who received tonsillectomy. Methods: We used data from the Taiwan National Health Insurance Research Database. The tonsillectomy group (case group) and the tonsillectomy-free group (comparison group) were matched at a ratio of 1:4 by demographic data, comorbidities, medical confounders, and the index date. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Results: We identified 2021 patients as the case group and matched 8084 individuals as the comparison group. The adjusted HR (aHR) of psoriasis was 0.43 (95% CI, 0.22-0.87; P < .05). The study population is composed of a mainly male (65%) and young population (mostly younger than 50 years). Notably, patients with rheumatoid arthritis increased the risk of psoriasis (aHR, 3.97; 95% CI, 1.17-13.48; P < .05). In our stratification analysis, the risk of psoriasis decreased in almost all subgroups. Limitation: Our database did not include information on genome and the subtypes of psoriasis. Conclusion: Our study showed a decreased risk of psoriasis in the tonsillectomy group after adjustment for baseline characteristics, comorbidities, and medical confounders compared with the reference group.
