Impact of Underlying Conditions on Zoster-Related Pain and on Quality of Life Following Zoster

Background: Chronic conditions have been investigated as risk factors for developing zoster, but in patients suffering from zoster, the impact of underlying conditions in zoster-related pain and quality of life (QOL) remains unclear. Methods: We performed a post hoc analysis of a prospective cohort study in immunocompetent zoster patients aged 50 years or older, conducted by general practitioners in Italy between 2009 and 2010. Zoster symptoms, pain intensity and characteristics, and physical and mental health scores were assessed at baseline (zoster diagnosis) and at 1, 3, and 6 months of follow-up. Results: Among 413 patients enrolled in the study, 73% (303/413) suffered from underlying conditions of which 69% (209/303) were aged 65 or older. Cardiovascular diseases (75%), diabetes (24%), and respiratory diseases (17%) were most frequent. One to three months after onset, zoster patients with underlying conditions experienced more intense zoster-related pain than those without. QOL scores were significantly lower in patients with underlying conditions, and age-adjusted difference in QOL scores between the groups increased over time, demonstrating a slower recovery for patients with underlying conditions. Conclusions: In addition to age, the main risk factor of zoster occurrence and severity, the presence of underlying conditions results in more painful and impactful zoster episodes, creating a significant burden for these patients.