What Is Post Herpetic Neuralgia?

Post herpetic neuralgia is a chronic pain condition that can occur as a complication of shingles. It starts immediately after an episode of shingles and it is characterized by persistent pain in the same location of the body that had been affected by shingles. Post herpetic neuralgia isn’t dangerous, but the pain can negativity affect your quality of life. The condition is diagnosed based on clinical symptoms and physical examination. While there is not a reliable way to predict whether you will progress to post herpetic neuralgia after shingles, having a weak immune system can predispose you to the chronic pain condition. And if you develop post herpetic neuralgia, there is no cure for it, but the symptoms can usually be managed with medication or interventional procedures. 

Symptoms

The pain of post herpetic neuralgia is intense and difficult to ignore. It can be present most of the time, but it can wax and wane in severity throughout the day or from day to day. It may keep you from sleeping and it can even affect your ability to concentrate. 

Before you would have the emergence of post herpetic neuralgia, you would have experienced shingles, which is characterized by a localized area of pain and a blistering rash. The skin lesions of shingles generally heal, but for someone who develops post herpetic neuralgia, the pain continues for three months or longer.

With post herpetic neuralgia, the pain that is usually more severe than the pain of shingles and it lingers after the rash resolves. 

The sensation of post herpetic neuralgia can be described as:

• Burning 
• Stabbing 
• Aching 
• Throbbing
• Sharp 
• Deep
• Intense

The sensations caused by post herpetic neuralgia don’t move around or change location, and the condition affects only one side of the body. Like shingles, post herpetic neuralgia is localized to a dermatome, which is an area of the body that corresponds to a sensory spinal nerve root. A dermatome is generally shaped like a ribbon winding around on one side of the face or body. 

Complications 

Post herpetic neuralgia can cause severe distress. It can interfere with your quality of life and it can lead to issues like sleep disturbances, depression, anxiety, and irritability. Treatment can reduce these effects. 

While the condition doesn’t cause skin lesions, excessive scratching of painful areas can cause cuts or bruises, possibly with permanent scarring of the skin.

Post herpetic neuralgia can resolve after months or years. Treatment is associated with a better chance of resolution, although the condition can resolve on its own. 

Causes

Post herpetic neuralgia is a type of neuropathy (nerve damage). It affects approximately 8 to 13% of people who get shingles.

Shingles is caused by reactivation of herpes zoster, which is the virus is that causes chicken pox. After a routine chicken pox infection, the virus lies dormant (inactive) in a dermatome, and it can be reactivated due to illness or a weak immune system.

The reactivation produces the rash and the pain due to inflammation of the nerve. Shingles is a short-lived condition that generally resolves on its own after several weeks. 

It isn’t possible to predict whether you are likely to have post herpetic neuralgia after an episode of shingles, but there some factors that are associated with a higher likelihood of having post herpetic neuralgia after shingles. 

Risk factors include:

• Low immune function 
• Older age 
• Severe pain while experiencing shingles 
• The need for high amounts of pain medication 
• Diabetes 
• Cancer
• Delayed pain treatment during the episode of shingles

Nerve Damage 

Research shows that post herpetic neuralgia is associated with severe inflammation of the affected nerve that continues even after the reactivated herpes zoster virus is no longer active.

Additionally, the nerve can become damaged. The myelin coating, which is a special fatty protective layer that surrounds nerves, can be diminished in people who have post herpetic neuralgia.

And the nerve axon, which is the part of the nerve that sends signals, can be injured as well, resulting in atrophy (shrinking of the nerve fiber). Experts suggest that the pain of shingles and post herpetic neuralgia may induce an inflammatory response that harms the affected nerve.

Sometimes the myelin damage can heal without treatment, and a few of the treatments used for treatment of refractory post herpetic neuralgia are aimed at repairing the nerve damage.

Diagnosis

Post herpetic neuralgia is diagnosed based on a medical history and physical examination. A recent episode of shingles almost always precedes the condition and the location of pain is the same as that of the previous shingles rash and pain. 

Your healthcare provider would do a physical examination to examine the area of your sensory complaints and to see if your pain matches up to a dermatome. Your healthcare provider will also check your skin for wounds or injuries that could be causing the pain.

You are unlikely to need diagnostic testing as part of your evaluation for post herpetic neuralgia.

However, if your symptoms or your physical examination are not typical, your healthcare provider may order tests to rule out other causes of your pain. For example, if you have pain in multiple locations, weakness, a fever, skin lesions, growths, lumps, or unusually tender areas, you would need diagnostic testing to ensure that you don’t have another cause of your pain besides post herpetic neuralgia.

Tests you may have include: 

• Blood tests: An infection, such as an abscess, can cause severe pain. This can be detected with an imaging test, but a complete blood count (CBC) can reveal an elevated white blood cell count (WBC), which is also a sign of an infection. 
• Imaging tests: If you have weakness along with your pain, it could be caused by a problem like a pinched nerve or a growth. An imaging test can identify spine lesions or tumors near the spine or elsewhere on the body. Post herpetic neuralgia does not cause abnormalities on imaging tests. 
• Electromyography (EMG) and/or nerve conduction study (NCV): Sensory loss, weakness, or pain that affects more than one part of the body can be an indication of nerve disease. Issues like peripheral neuropathy can be identified with these diagnostic nerve tests. 
• A biopsy: If you have a growth or a mass near the areas of your pain, it can be a benign tumor or cancer. A biopsy of the growth can help determine what it is and help direct future treatment planning. 

Treatment

Your treatment for post herpetic neuralgia can include a variety of approaches that include lifestyle modification, topical and oral medication, interventional procedures, and complementary and alternative (CAM) treatment.

Often, a combination of treatment strategies is most effective for control of symptoms and helps keep your medication dose low to avoid side effects. 

Lifestyle Modification

You can’t make post herpetic neuralgia go away with simple habits, but you can reduce its effect on your quality of life. If you have noticed that touching or wearing certain fabrics exacerbates it, or that sleeping in a certain position worsens the pain, you can make adjustments to reduce these exacerbating factors.

Any lifestyle modifications you can make may reduce your need for medical treatment and interventions. 

At home routines like using an ice pack can help reduce your pain at times, and you can consider this option if it works for you. Some people may notice that massaging the skin, taking a warm bath, or exercise can help.

It is important that you get enough sleep, because sleep deprivation increases your body’s sensitivity to pain. 

Medication

A number of over the counter (OTC) and prescription medications are used to reduce the painful effects of post herpetic neuralgia. The key with taking medication is to avoid high doses because there are many side effects associated with pain medication—such as drowsiness, balance issues, and even addiction. 

Topical medications: Topical treatments include medications that decrease sensation for several hours. Over the counter capsaicin, tiger balm, and lidocaine can be effective. These treatments come as creams, gels, sprays, patches, and roll on and they work as the active ingredients are absorbed into the skin. They are generally safe, but they should be used only as directed and shouldn’t be applied to open wounds.

Be sure to talk to your healthcare provider if you want to use topical OTC for treating the symptoms of your post herpetic neuralgia. Additionally, these topical treatments are also available in prescription strength formulations, and you and your healthcare provider can discuss the best option for you. 

Oral OTC treatment: Oral treatments include OTC pills and tablets like acetaminophen, non-steroidal anti inflammatories (NSAIDs) like ibuprofen, and antihistamines like diphenhydramine. These treatments might relieve the pain for several hours, but they all have potentially serious side effects, especially when taken for weeks on end and/or in high doses.

Prescription OTC treatment: There are a number of prescription treatments used for managing the symptoms of post herpetic neuralgia. The most commonly prescribed medications for this condition include antidepressants such as amitriptyline and anticonvulsants such as gabapentin.

These treatments are commonly used for managing neuropathic pain, but they don’t cure the underlying condition. Medications like opioids are sometimes prescribed for reducing the pain of post herpetic neuralgia, but they can be dangerous and addictive, so they aren’t generally recommended. 

Interventional Procedures

Treatment interventions like injections of lidocaine or other anesthetics are used to reduce sensation to the painful area. Generally, pain injections are effective for several months and may need to be repeated after the treatment wears off. You might be able to stop taking medications for several months after having a pain injection, or you might be able to use a lower dose of your oral or topical medication.

And surgical treatments have been used as a method of eliminating the pain of post herpetic neuralgia for the long term. Treatments include nerve ablation (cutting the sensory branch of the nerve) to permanently eliminate sensation. This treatment should not cause any weakness, but normal sensation is lost as a result of surgical nerve ablation.

Nerve stimulation has also been used as a treatment. This involves a procedure in which a device is implanted to provide electrical signals to the nerve to moderate the pain sensation.

Another procedure, autologous fat grafting, has recently emerged. This involves taking fat from your own body and injecting it into the area of pain. This type of surgery has shown promise in early studies.

CAM

Alternative therapies have not been shown to cure post herpetic neuralgia, but strategies like meditation, acupuncture, and biofeedback can help you relax and cope with the pain, potentially reducing the effects of the condition on your day to day life.

You can discuss these alternative approaches with your healthcare provider, but keep in mind that you might still need to continue using some traditional medical therapy as well.

Coping

Living with post herpetic neuralgia is challenging. It is important that you acknowledge your pain and communicate with those around you so that your loved ones will know that you need to take care of yourself.

If certain things—like heat or cold—make your pain worse, don’t hesitate to ask for accommodations so you can avoid exacerbating factors. Additionally, you might need more rest, or you may need some quiet time to give yourself a break if you feel overstimulated.

Consider talking with a therapist so you can express your feelings and your needs as you create a plan for managing your pain and your life with post herpetic neuralgia.

A Word From Verywell

Post herpetic neuralgia is a chronic type of neuropathic pain that can cause severe distress for people who experience it. Living with pain can make you irritable and can interfere with your peace of mind, relationships, and work. The situation can be especially difficult to understand because there are no visible skin changes that accompany it. It may take some time for you and your healthcare provider to find the best treatment plan for you, but achieving pain relief is well worth the patience and effort.