# Incidence of Late-Onset Psoriasis Following Tonsillectomy: A Longitudinal Follow-Up Study Using a National Health Screening Cohort

## TL;DR

This study found that tonsillectomy does not significantly reduce the risk of developing late-onset psoriasis in Korean adults.

## Contribution

The study provides new evidence on the lack of preventive effect of tonsillectomy for late-onset psoriasis in a national cohort.

## Key findings

- The incidence of psoriasis was 1.30% in the tonsillectomy group and 1.20% in the control group.
- The hazard ratio for psoriasis was not significantly different between the tonsillectomy and control groups.
- The cumulative probability of developing psoriasis was similar between the two groups.

## Abstract

Tonsillectomy has been suggested as a potential intervention to resolve psoriasis; however, its preventive effects on the development of psoriasis remain unclear. This study aimed to investigate the risk of developing late-onset psoriasis among a Korean adult population who had undergone tonsillectomy. Data from the Korean National Health Insurance Service-Health Screening Cohort between 2002 and 2019 were utilized. Out of a total of 514,866 participants, 1082 participants aged 40 years or older who had undergone tonsillectomy were matched with 4328 control participants using overlap weighting adjustment based on the propensity score. The incidence and hazard ratio (HR) of psoriasis were calculated for both tonsillectomy and control groups. The incidence rates of psoriasis were 1.30% in the tonsillectomy group and 1.20% in the control group. The incidence of psoriasis (overlap-weighted HR = 1.08, 95% confidence of interval = 0.69–1.69, and p = 0.732) did not differ significantly between the patients who underwent tonsillectomy and those in the control group. The cumulative probability of developing psoriasis was not different between the two groups (Log-rank test: p = 0.440). These findings were consistent across subgroups divided by age, sex, income, and region of residence. We found that tonsillectomy did not confer a preventive effect on the development of late-onset psoriasis in the Korean adult population.