Prevalence and impact on quality of life of post-herpetic neuralgia in French medical centers specialized in chronic pain management: The ZOCAD study

Abstract Objectives (1) We had for aim to determine the rate of patients consulting for post-herpetic neuralgia (PHN) in centers specialized in the management of chronic pain, (2) to assess the burden of PHN, (3) to compare the impact of PHN between new (newly consulting for PHN) and known (already treated by pain specialists) patients. Patients and methods We conducted a prospective multicenter observational study including all chronic pain outpatients consulting for 3 consecutive weeks. The impact of PHN was assessed with the ZBPI, SF12, HADS, and a non-validated disability questionnaire. Results Among the patients, 4518 consulted 54 specialized centers from January 24th to July 21st 2008: 2.6% of patients (but 10.9% of patients 70 years of age or more) reported PHN. The acute herpes zoster episode had occurred more than 13.3 months before inclusion for half of the patients. 108 of the 118 PHN patients (33 new and 75 known) completed the questionnaires. Their mean scores were 3.7 (SD, 2.6) for ZBPI and 34.4 (SD, 10.9) and 55.9 (SD, 11.4) for SF12 PCS and MCS; 38% and 42% of PHN patients had HADS anxiety and depression scores > 10. Nearly all PHN patients had received antiepileptic and analgesic drugs. Tricyclic antidepressants and lidocaine patches were more frequently administered to known than to new patients. Pain relief was more effective for known than for new patients. Conclusions PHN is a frequent cause of visit in French medical centers specialized in chronic pain management long after the rash has disappeared, and a reason for treatment with drugs that should be prescribed cautiously in elderly patients.