Authors: Forbes HJ et al., Neurology 2016 Jul 5; 87:94
In a large prospective database study, increased risks were seen in older patients and those with severe immunosuppression.
Postherpetic neuralgia (PHN) following acute herpes zoster remains a significant cause of neuropathic pain, especially in older patients. Treatment results of this severe and long-lasting pain syndrome are often disappointing. To examine the effect of antivirals, and other potential risk factors, on PHN risk among zoster patients, researchers used prospectively collected data from the Clinical Practice Research Datalink, a U.K. general practice database. The study cohort included patients with first-ever zoster, followed to determine who developed PHN.
Of 144,959 patients with zoster diagnosed between January 1, 2000, and December 31, 2011, 119,413 (60% female; median age, 61) were eligible for inclusion. Of these, 6956 (5.8%) developed PHN. Risk for PHN rose with age; patients between 50 and 79 years had the steepest increase in risk for PHN. Other important risk factors for PHN were immunosuppressive conditions and therapies: Patients with lymphoma, leukemia, or myeloma or recently taking corticosteroids had twice the risk for developing postherpetic neuralgia of other patients. Systemic lupus erythematosus (SLE) also was frequently associated with PHN. Antiviral drugs did not have a clear effect on PHN risk, but may have slightly reduced the risks associated with leukemia, SLE, chronic obstructive pulmonary disease, and smoking.
Currently the only proven intervention to prevent PHN is varicella-zoster virus vaccination, used in elders and in patients with identified risk factors for PHN, which should include immunosuppression. Unfortunately, the high cost of the vaccine limits its use in poor countries. A more cost-effective therapy that prevents PHN is lacking.