ABSTRACT
BACKGROUND: Although most cases of herpes zoster (HZ) are self-limited, lymphoma patients are at greater risk for recurrences and more serious and atypical complications that can delay scheduled anti-lymphoma treatment or prevent its continuation. PATIENTS AND METHODS: This is a cohort study with a retrospective chart review of 415 patients diagnosed with lymphoma to determine the incidence and risk factors for developing HZ among this population. Data collected included date of diagnosis, patient's age, last follow-up or death, stage and presentation of lymphoma, treatment type, baseline laboratory tests, and comorbidities. Patients with a diagnosis of HZ at any time during their course of illness were identified. Patients were divided into various subgroups to analyze their risk of developing HZ individually. The frequencies of each categorical variable were compared with χ2 tests. Relative risks were calculated using 95% confidence intervals (CIs). RESULTS: During a median follow-up of 8.9 years, 46 cases of HZ were identified, with an overall incidence density of 11.1%. Higher rates of HZ were associated with lymphocytopenia (P = .038), presentation (P = .030), stage (P = .034), autologous stem cell transplant (P = .019), multiple courses of chemotherapy (P = .035), and fludarabine therapy (P = .002). Those who received what we labeled as 'highly immunosuppressive chemotherapy' had 2.9 times the risk to develop HZ than those who did not receive this therapy (95% CI, 1.47-5.623; P < .001). CONCLUSIONS: Receiving highly immunosuppressive chemotherapy is an independent risk factor for developing HZ. Patients with the risk factors described here might benefit from antiviral prophylaxis against HZ.