Peptic ulcer as a risk factor for postherpetic neuralgia in adult patients with herpes zoster.

Postherpetic neuralgia is the most common complication of herpes zoster. Identifying predictors for postherpetic neuralgia may help physicians screen herpes zoster patients at risk of postherpetic neuralgia and undertake preventive strategies. Peptic ulcer has been linked to immunological dysfunctions and malnutrition, both of which are predictors of postherpetic neuralgia. The aim of this retrospective case-control study was to determine whether adult herpes zoster patients with peptic ulcer were at greater risk of postherpetic neuralgia. Adult zoster patients without postherpetic neuralgia and postherpetic neuralgia patients were automatically selected from a medical center's electronic database using herpes zoster/postherpetic neuralgia ICD-9 codes supported with inclusion and exclusion criteria. Consequently, medical record review was performed to validate the diagnostic codes and all pertaining data including peptic ulcer, Helicobacter pylori (H. pylori) infection and ulcerogenic medications. Because no standard pain intensity measurement exists, opioid usage was used as a proxy measurement for moderate to severe pain. In total, 410 zoster patients without postherpetic neuralgia and 115 postherpetic neuralgia patients were included. Multivariate logistic regressions identified 60 years of age and older, peptic ulcer and greater acute herpetic pain as independent predictors for postherpetic neuralgia. Among etiologies of peptic ulcer, H. pylori infection and usage of non-selective nonsteroidal anti-inflammatory drugs were significantly associated with the increased risk of postherpetic neuralgia; conversely, other etiologies were not significantly associated with the postherpetic neuralgia risk. In conclusion, 60 years of age and older, peptic ulcer and greater acute herpetic pain are independent predictors for postherpetic neuralgia in adult herpes zoster patients.