Postherpetic Neuralgia After Herpes Zoster and Incident Dementia Risk

This retrospective observational cohort study uses de-identified electronic health record data from the TriNetX Global Collaborative Network to evaluate whether postherpetic neuralgia after herpes zoster is associated with an increased risk of incident dementia. Adults aged 40 to 120 years with incident herpes zoster between 1 October 2015 and 31 December 2024 are identified using diagnostic codes. Postherpetic neuralgia is defined by International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) codes B02.22 or B02.29 recorded between 90 and 365 days after the index herpes zoster date, and comparators have no such codes within 365 days after index. The primary analysis uses 1:1 propensity score matching and a 365-day landmark design, including only individuals alive and free of dementia at the landmark. Time-to-event analyses estimate hazard ratios for incident dementia and related outcomes.