Long‐term risk of herpes zoster following COVID‐19: A retrospective cohort study of 2 442 686 patients

The long‐term risk of herpes zoster (HZ) after recovery from a SARS‐CoV‐2 infection is unclear. This retrospective cohort study assessed the risk of HZ in patients following a COVID‐19 diagnosis. This retrospective, propensity score‐matched cohort study was based on the multi‐institutional research network TriNetX. The risk of incident HZ in patients with COVID‐19 was compared with that of those not infected with SARS‐CoV‐2 during a 1‐year follow‐up period. Hazard ratios (HRs) and 95% confidence intervals (CIs) of HZ and its subtypes were calculated. This study identified 1 221 343 patients with and without COVID‐19 diagnoses with matched baseline characteristics. During the 1‐year follow‐up period, patients with COVID‐19 had a higher risk of HZ compared with those without COVID‐19 (HR: 1.59; 95% CI: 1.49–1.69). In addition, compared with the control group patients, those with COVID‐19 had a higher risk of HZ ophthalmicus (HR: 1.31; 95% CI: 1.01–1.71), disseminated zoster (HR: 2.80; 95% CI: 1.37–5.74), zoster with other complications (HR: 1.46; 95% CI: 1.18–1.79), and zoster without complications (HR: 1.66; 95% CI: 1.55–1.77). Kaplan–Meier curve analysis (log‐rank p