Allodynia can be so severe that patients cannot bear the touch of bedsheets or clothing. Elderly patients' quality of life can be severely affected. The seeds of postherpetic neuralgia are sown early in life, often with varicella-zoster virus, which always attempts to reappear and reactivate later on. The immune system usually prevents this, but when it is unable to, the virus will surface in other ways. Prolonged acute pain is the central problem in herpes zoster and ophthalmic zoster.
Shingles usually develops in elderly persons with reduced immune function.
Although there have been no clinical trials testing anticonvulsants, they may be useful early on. While the antidepressant amitriptyline has shown some promise in a small trial conducted by Bowsher 5 in England, it is not a favored geriatric drug because of side effects. However, other tricyclic antidepressants are still worthy of investigation. Dr. Schmader discussed antiviral therapy, which includes acyclovir, famciclovir, and valacyclovir. Famciclovir and valacyclovir have better bioavailability and may reduce the length of pain.