The postherpetic neuralgia (PHN) is a common complication associated with herpes zoster (shingles) where the pain continues to trouble the patient even after complete healing of shingles and disappearance of blisters and rash. The individual is said to have postherpetic neuralgia when the pain fails to cease even after 1 month of the onset of shingles. postherpetic neuralgia rarely takes place in patients with below 50 years of age, suffering from shingles. The severity, length, and incidence of postherpetic neuralgia increase with the age of the individuals, but elderly patients generally experience mild pain only. Most incidents of postherpetic neuralgia spontaneously heal in 2 to 3 months1.
What Is The Prognosis For Postherpetic Neuralgia?
Good prognosis can be observed in most of the individuals suffering from postherpetic neuralgia. However, pain medicines may need to be taken for more than 1 to 3 months on a consistent basis. But, some patients have a poor prognosis, suffering from serious pain for a longer period that may last over 3 months to more than a year. It may significantly decrease their overall life quality and daily activities. Although the disorder is usually not fatal, sometimes it may lead to permanent damage to the nerves6.
The prevention of postherpetic neuralgia depends on the successful prevention of developing shingles. Thankfully, there is a Zostavax vaccine for shingles, which is close to 70% efficient in shingle prevention. People over 50 years (according to the FDA) and 60 years (according to CDC) are recommended to have the vaccine to prevent shingles. But the vaccine is not suitable for pregnant women or individuals with an immunodeficiency. People with the previous history of anaphylactic reaction against neomycin and gelatin, two major components of the vaccine should also avoid vaccine6.
Age is the primary risk factor of postherpetic neuralgia with people over the age of 70 has a risk factor of 75%. Individuals over 60 years of age, on the other hand, have a 60% chance of suffering from postherpetic neuralgia after developing shingles. Family is another important risk factor. Individuals with close family members who have acquired postherpetic neuralgia are at a greater risk compared to those with no postherpetic neuralgia history in the family2.
Pain And Time Frame Of Healing
Only about 9% -15% of individuals with shingles have postherpetic neuralgia in the later stages. The length of PHN or the healing time varies widely among patients. For the majority of the patients, the pain goes away within the first 2 – 3 months. However, one-third of postherpetic neuralgia patients suffer from the pain for more than 3 months, while one-fifth of the patients have the pain lasting for over a year or even longer3.
Individuals over the age of 70 years have the highest chance of acquiring postherpetic neuralgia. But even in this age group, only 25% of the patients experience pain for over months and 10% suffer from pain persisting for over 1 year. These pains are less severe and often mild compared to postherpetic neuralgia patients of younger age 3.
Associated Complications
Postherpetic neuralgia develops as a result of shingle complication. Dependence on pain medicines is a severe postherpetic neuralgia complication. Several individuals fail to lead a normal lifestyle due to continual pain. It hugely constrains the patients to take part in exercise leading to other lifestyle-related issues in older age. Many people suffer from a sleep disorder and limited to no activity as the affected area becomes too sensitive to touch. Wearing clothes may also become a problem because of this touch sensitiveness that triggers burning pain. This constant pain makes the patient go for pain killers and sometimes the doctor may prescribe a high dose of analgesics and other drugs such as opioids to control the pain3,4,5.
Prolonged use of these drugs makes the patient addicted to them. Opioids can cause serious constipation in patients. In a few instances, it is found that the patients also suffering from weakness in muscles.
Conclusion
Studies on the prognosis of postherpetic neuralgia patients have revealed that in many instances the disorder is cured without any medical intervention. Patients suffering from postherpetic neuralgia for longer duration need more analgesics, antidepressant or opioid therapy.
- Johnson RW. Herpes zoster and postherpetic neuralgia. Expert review of vaccines. 2010;9(sup3):21-26.
- Gan EY, Tian EAL, Tey HL. Management of herpes zoster and post-herpetic neuralgia. American journal of clinical dermatology. 2013;14(2):77-85.
- Drolet M, Brisson M, Schmader KE, et al. The impact of herpes zoster and postherpetic neuralgia on health-related quality of life: a prospective study. Cmaj. 2010;182(16):1731-1736.
- Jeon YH. Herpes zoster and postherpetic neuralgia: practical consideration for prevention and treatment. The Korean journal of pain. 2015;28(3):177.
- Mallick-Searle T, Snodgrass B, Brant JM. Postherpetic neuralgia: epidemiology, pathophysiology, and pain management pharmacology. Journal of multidisciplinary healthcare. 2016;9:447.
- Opstelten W, Zuithoff NP, van Essen GA, et al. Predicting postherpetic neuralgia in elderly primary care patients with herpes zoster: prospective prognostic study. Pain. 2007;132:S52-S59.
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