Postherpetic neuralgia (PHN) is a common complication of herpes zoster or shingles. If a person has been infected by chicken pox virus or varicella virus or herpes zoster at a young age, then this virus remains dormant throughout his life. It gets reactivated when one’s immune system gets weak (usually at the old age) in the form of shingles that may complicate into postherpetic neuralgia. It can be prevented if shingles are prevented with various ways discussed below.
What Are The Ways To Prevent Postherpetic Neuralgia?
Postherpetic neuralgia is a painful condition that appears after an episode of shingles or herpes zoster. It happens due to reactivation of the virus named herpes zoster.
Shingles itself develop due to reactivation of herpes zoster virus which had infected the patient as chicken pox in his childhood or adolescence. It remains dormant in the nerve cells since childhood and gets reactivated years after.(1)
Prevention of postherpetic neuralgia also depends on the severity of shingles. If the shingles are treated with antiviral medicines in the early stages, the appearance of complications related to shingles can be reduced to a great extent.(2)
In severe cases of shingles, there is a higher risk of developing complications especially postherpetic neuralgia. It can be prevented if antiviral drugs are taken from the early stages. In many research studies, it has been stated that antiviral treatment involving acyclovir, famciclovir, and valacyclovir are helpful to treat the severity of acute herpes zoster infection.(3) It is beneficial more when they are consumed within 2-3 days of the appearance of shingles.(4) It is also noted that medication is more effective when there is the shedding of skin and rash is on the way of healing. The duration of this shedding is reduced with faster healing of the rashes and severity of acute pain related to rash reduces significantly. However, the research studies do not clarify the use of these drugs to be consumed singly has similar beneficial effects on the risk of prolonged pain.(3)
At the same time, it is also found in the research studies that patients above 50 years are on antiviral therapy is not able to prevent postherpetic neuralgia in almost 20 % of the cases. The people who are above the age of 50 years develop chronic pain within 6 months after the appearance of rash despite being treated with antiviral therapy. New antiviral therapy has been studied to find out effective treatment.(2)
Corticosteroids are being studied in various researches. It is found that corticosteroids are effective to relieve the acute pain of shingles. It is also found that they are useful to prevent postherpetic neuralgia. It is used for rare cases. However, it is less effective in the prevention of postherpetic neuralgia. Steroids and analgesics can effectively reduce the level of inflammation reducing the occurrence of postherpetic neuralgia as steroids protect nerve fibers and analgesics reduce the pain sensation.(2)
Tricyclic antidepressants are found to be promising in the treatment of postherpetic neuralgia and it is also found to be promising in the prevention of postherpetic neuralgia in 50 % of cases if used early during the appearance of the rash.(2)
FDA has approved a vaccine named Zostavax for the prevention of shingles. It is recommended for old adults who are above 60 years. It has been found that this vaccine can reduce the risk of shingles by 50 %. It is recommended for people who are above 50 years who have skin problems and a weak immune system. It is also found that after this vaccination, shingles develop afterward are less painful and less severe.(4)
Postherpetic neuralgia is a common complication of shingles. Many medicines of shingles used for its treatment such as antiviral medicines or corticosteroids are known to prevent postherpetic neuralgia. FDA has approved Zostavax that can prevent shingles and postherpetic neuralgia in almost 50 % of people who had chicken pox in their childhood.