Nerve pain remaining after rashes from the shingles virus (varicella-zoster) have disappeared is referred to as Postherpetic Neuralgia (PHN). While PHN-related pain often eases in time, the initial pain can sometimes be as unbearable as what was experienced with shingles, although some people only have mild discomfort. Medication is often helpful at managing PHN until the lingering effects of the virus completely go away.
What Causes PHN Pain?
Postherpetic neuralgia is caused by nerves that have become inflamed, irritated, or damaged as a result of the shingle virus and the accompanying rash. Scar tissue next to nerves or along adjacent parts of the spinal cord may contribute to it. Discomfort is often felt in the same area previously affected by the rash. In 5 out of 10 people with PHN, symptoms last about three months.
The nerve damage in cases of Postherpetic Neuralgia is caused by the underlying condition in which the shingles interrupts normal nerve functioning. The damaged nerve sends random pain signals to the brain, causing the individual to a feel a deep, throbbing pulse along the nerve endings. Research suggests that scar tissue is created near the nerves when the body experiences shingles, and those scars create pressure that confuses the nerves.
The direct cause of postherpetic neuralgia is shingles, a condition that develops in patients who have had chickenpox and, later in life, experience a condition in which the immune system is suppressed. This often occurs when the individual takes certain medications or undergoes chemotherapy. The pain induced by postherpetic neuralgia, as a result of nerves damaged by shingles, can last months or even years, if untreated.
Wearing loose-fitting clothing or taking cool baths may provide relief. Tricyclic antidepressants such as amitriptyline tend to work better for nerve pain. Traditional painkillers aren’t usually effective. Anti-epileptic medicines like gabapentin may also help control nerve impulses.
Treatment may also include:
Pain either returning or continuing more than a month after shingles has cleared is classified as PHN. Shingles can affect anyone who previously had chickenpox, which is approximately 95 percent of all adults in the United States. PHN is less common and is often mild in people under fifty. For seniors who have had shingles, however, it can be more severe, suggesting a greater chance of experiencing PHN when shingles develops later in life.
It’s fairly simple to prevent the onset of postherpetic neuralgia, especially because it primarily occurs in patients over 50 or 55 years of age. For those 60 or older, the Center for Disease Control advises a dose of herpes zoster vaccine (Zostavax), though the vaccine has recently been approved for those as young as 50. Patients in these age ranges can receive the preventative treatment without having to undergo serologic testing. A history of varicella virus infection also does not bar persons from receiving the herpes zoster vaccine.
While the treatment is 66.5% effective in preventing postherpetic neuralgia, most individuals don’t receive the vaccination. Most patients aren’t aware of postherpetic neuralgia and those that do know of the condition feel they don’t need the vaccine. This reluctance to prevent postherpetic neuralgia is, in part, due to the cost, which nears $200 per dose. Additionally, the doses must be kept frozen with constant monitoring by healthcare professionals, suggesting most doctors won’t keep the vaccine on hand. Instead, patients may need to visit a pharmacy to receive the treatment, which is something most doctors recommend, in spite of the fact that most insurance carriers won’t cover the cost of the vaccine.