postherpetic neuralgia

What is postherpetic neuralgia

Postherpetic neuralgia is a form of chronic nerve pain that continues in the area affected by shingles rash that has disappeared. Postherpetic neuralgia is the most common complication of shingles. It’s still not clear how it can be prevented or what the best treatment is. The shingles rash and pain are caused by the varicella zoster virus (the same virus that causes chicken pox). Shingles is also called herpes zoster. The pain associated with the shingles rash normally goes away when the rash goes away. This usually happens after two to four weeks, but most commonly only lasts for 2-3 days. Postherpetic neuralgia is not diagnosed until 2-3 months after the shingles rash has healed. If similar but refractory pain persists at this point, then the individual has more than likely developed postherpetic neuralgia. Pain that continues for longer is referred to as post-herpetic neuralgia and post-herpetic neuralgia pain can be difficult to treat and become very intense in some cases.

Pain associated with post-herpetic neuralgia can be very intense, often described by patients as deep, aching and unbearable. In some cases, even a light touch, like the pressure of a shirt or gust of wind, can cause intense pain. The skin is often overly sensitive and itchy as well. This can make it difficult or painful to wash yourself, turn over in bed, or hug someone. Post-herpetic neuralgia pain and itching can be very severe and might keep you from sleeping. Because of the intensity of postherpetic neuralgia pain, it can interfere with day activities, including sleep and appetite. Depression is common because of the severe pain and social isolation that can occur.

Many people with post-herpetic neuralgia make a full recovery within a year. But symptoms occasionally last for several years or may be permanent. Postherpetic neuralgia affects 10–20% of individuals who have had shingles. Older people are particularly at risk. People over age 60 who have had shingles have as much as a 50 percent chance of developing postherpetic neuralgia.

The average age for contracting postherpetic neuralgia is 68 and both men and women are equally as likely to contract the condition.

Anyone that contracted chicken pox at any stage of their life is at risk of developing herpes zoster and therefore postherpetic neuralgia. The reactivation of the virus most commonly occurs in people that have a decreased immunity. This includes:

  • The elderly;
  • People with diseases that affect the immune system, like HIV; or
  • People with diseases that require treatment which has an effect on the immune system, such as treatment with chemotherapy for cancer.

People at risk need to be closely monitored so that if herpes zoster occurs, their doctor can immediately intervene. People that are not actively reminded of the risk of herpes zoster are more likely to be diagnosed late and so the risk of developing postherpetic neuralgia is greater.

What increases the risk of postherpetic neuralgia pain?

The risk of developing post-herpetic neuralgia increases with age. Four weeks after getting shingles,

  • 27% of 55- to 59-year-olds and
  • 73% of over 70-year-olds had nerve pain.

Women seem to be more likely to have longer-lasting nerve pain than men. Post-herpetic neuralgia is also more likely to develop if your eyes were affected by shingles.

There are a variety of effective pain relief medications, but unfortunately there is no cure for postherpetic neuralgia. In most cases, the pain of postherpetic neuralgia subsides with time.

Medication can ease the symptoms of postherpetic neuralgia neuralgia, although it may not relieve the pain completely. Widely available painkillers, such as paracetamol and ibuprofen, don’t usually help, so your doctor may prescribe a different type of painkiller.

Some medicines used to treat depression also work for nerve pain and are sometimes used for post-herpetic neuralgia.

How long does postherpetic neuralgia last

Luckily many people with post-herpetic neuralgia make a full recovery within a year. However, for approximately 40% of postherpetic neuralgia sufferers the pain continues long-term. And symptoms occasionally last for several years or may be permanent.

Postherpetic neuralgia complications

Depending on how long postherpetic neuralgia lasts and how painful it is, people with the condition can develop:

  • Depression
  • Fatigue
  • Difficulty sleeping
  • Lack of appetite
  • Difficulty concentrating

Postherpetic neuralgia causes

The varicella zoster virus causes both chickenpox and shingles.

In post-herpetic neuralgia, the virus causes inflammation of the nerves under the skin of the affected area. Neuralgia is a medical term for pain resulting from nerve inflammation or damage.

The neuropathic pain involved in postherpetic neuralgia is thought to be caused by abnormal pain signals in the nervous system that occur as a result of the damage caused by the virus. These abnormal firing signals are thought to be related to one or more of:

  • De-afferentation: If the damage from inflammation from the herpes zoster is severe enough then it can result in de-afferentation of the nerves. This is the disruption of the impulses that are carried by the nerves.
  • Sensitization: The constant pain signalling that occurs during herpes zoster hypersensitizes the nerves which make them overly responsive to pain.
  • Abnormal pain interpretation: The damage to the nerves has the potential to cause the brain to interpret pain signals incorrectly. The person will then experience pain when there is no longer an external contributor, like inflammation.

It’s not clear why some people with shingles develop post-herpetic neuralgia, but increasing age, pain during the early stage of shingles and severe pain throughout an episode of shingles are all associated with an increased risk of the condition.

Risk Factors for postherpetic neuralgia

The major predisposing factor to postherpetic neuralgia is chicken pox followed, sometimes decades later, by herpes zoster. Not all people that experience herpes zoster will be affected by postherpetic neuralgia. In fact, the figures vary between 9 and 34%.

Although there is no definite way to determine which people will develop postherpetic neuralgia there are some probable indicators:

  • Those who experience more severe pain during the early stages of herpes zoster are more likely to experience postherpetic neuralgia;
  • The level of inflammation (the pain is often related to the level of inflammation during this stage which is therefore also a predisposing factor); and
  • The older a person is when they develop herpes zoster, the greater the risk they will develop postherpetic neuralgia. For patients younger than 50 the risk is very low, however for patients over 80 the risk is around 34%.

Postherpetic neuralgia prevention

There’s no definite way to prevent post-herpetic neuralgia. But if shingles is treated early with antiviral medication, the risk of complications such as post-herpetic neuralgia is reduced.

If you develop symptoms such as pain or a rash that suggests shingles, see your doctor as soon as possible to discuss taking an antiviral medication.

People who have a severe case of shingles or who are at a higher risk of developing complications are often advised to take antiviral (virus-fighting) drugs to try to prevent post-herpetic neuralgia. Several studies have tested whether antiviral therapy can actually prevent long-lasting nerve pain. They showed that treatment with the antiviral drug aciclovir did not prevent post-herpetic neuralgia: The same number of people still had pain both four and six months after having shingles – regardless of whether they had taken aciclovir or a dummy drug (placebo). There has not yet been enough research on the other antiviral drugs brivudine, famciclovir and valaciclovir to tell whether they might be able to prevent post-herpetic neuralgia.

In rare cases, corticosteroid therapy is also recommended for the prevention of post-herpetic neuralgia. Corticosteroids can be taken in the form of tablets or injected into a muscle. But studies have shown that they are not more effective than a placebo.

Epidural administration of steroids and analgesics at the level of inflammation has also been found to be effective in reducing postherpetic neuralgia occurrence. The steroids are thought to protect the neurons and the analgesics stop the continuous stimulation of pain.

At daily doses of around 10-25mg tricyclic antidepressants have been found to be a promising strategy to treat over 50 % of the pain in postherpetic neuralgia and have also been found to be moderately effective in prevention if used early once the rash has presented.

Having the shingles vaccination will help you avoid getting the infection in the first place. If you’ve had shingles before, the vaccine will also reduce your risk of getting it again. The herpes zoster vaccine (Zostavax) has been shown to greatly decrease the risk of shingles. The vaccine is approved by the Food and Drug Administration for adults age 50 and older and is recommended for all adults 60 and older who aren’t allergic to the vaccine and who don’t take immune-suppressing medications.

Postherpetic neuralgia symptoms

The main symptom of post-herpetic neuralgia is intermittent or continuous nerve pain that lasts 3 months or longer in an area previously affected by shingles.

The pain has been described as burning, stabbing, shooting, aching, throbbing or like electric shocks.

The affected area may also:

  • feel intensely itchy
  • be more sensitive to pain than usual
  • feel painful as a result of something that wouldn’t normally hurt, such as a light touch or cool breeze. Very light pressure, such as a gentle breeze or a brush of clothing, can cause some people intense pain, and this is for the most part unavoidable.

Continuing severe pain can have a major affect on quality of life. Commonly experienced side effects stemming from chronic pain include:

  • Loss of sleep and the consequences associated with fatigue;
  • Depression:
  • Loss of enthusiasm, motivation and sex drive ;
  • Negative impact on relationships and social life; and
  • Feelings of isolation, fear and anxiety can also occur.

Postherpetic neuralgia diagnosis

There are no specific tests available to test for post-herpetic neuralgia. However, people who have recovered from shingles and experience an ongoing pain in the region affected by the initial shingles rash, should contact their doctor to determine if they have developed postherpetic neuralgia.

Commonly, people with postherpetic neuralgia will experience a degree of sensory loss in the area innervated by the affected spinal segment. The response to a pinprick, heat changes and vibrations in that area will be less sensitive than surrounding unaffected areas but this will induce significantly more pain. It is suggested that this area is where spontaneous pain is experienced whereas the surrounding areas less affected by the virus will be the areas responsible for the feeling of allodynia. There is more likely to be a pain response to cold than to heat.

Postherpetic neuralgia treatment

No single treatment relieves postherpetic neuralgia in all people. In many cases, it takes a combination of treatments to reduce the pain.

There are some things you can do yourself to try to reduce the discomfort of post-herpetic neuralgia. Medication can also be used to help relieve the pain.

Home remedies

To help reduce the pain and irritation of post-herpetic neuralgia:

  • wear comfortable clothing – cotton or silk clothing usually causes less irritation
  • use cold packs – some people find cooling the affected area with an ice pack helps

Creams and plasters

Your doctor can prescribe treatments that you apply directly to the painful area.

Lidocaine patches

Lidocaine patches are sticking plasters that contain a local anesthetic. They can be useful when pain affects sleeping or daytime activity. They can’t be used for more than 12 hours at a time.

The US and UK have approved lidocaine 5% patches in the treatment of postherpetic neuralgia. The patch is placed somewhere comfortable on the torso, not where the pain is experienced or somewhere that is likely to be disrupted through daily routine. The patch slowly releases the local anesthetic throughout the week to help numb the pain. The patch needs to be replaced regularly.

Capsaicin cream

Capsaicin is the substance that makes chilli peppers hot. It’s thought to work for nerve pain by stopping the nerves sending pain messages to the brain.

Your doctor can prescribe capsaicin as a low-dose cream. You apply it to the affected area a few times a day, but only when the rash has healed. It works by changing the way the nerve endings function.

High-strength capsaicin patches can also be used to treat post-herpetic neuralgia. They’re available at specialist pain clinics and are applied as a single treatment in the clinic or at hospital. High-strength capsaicin patch is applied by trained personnel after using a numbing medication on the affected area. The process takes at least two hours, but a single application is effective in decreasing pain for some people for up to three months. If effective, the treatment can be repeated, usually every three months depending on how your symptoms have improved.

Medication

Medication may not stop the pain completely, but it can help reduce it. You may need to try a number of different types of medicine to find the one, or combination, that works best for you.

Painkillers (analgesics) are typically used to treat post-herpetic neuralgia. The right drug and dose will depend on how severe the pain is and how well tolerated the particular medicine is. So it’s important to describe the pain to your doctor in as much detail as possible, and to let them know what effects the drug is having – including any side effects.

There are two main classes of painkillers:

  • Non-opioid painkillers act on the outer (peripheral) nerves in the skin, the muscles and the organs. They are used to treat mild to moderate pain. Many of them, such as acetylsalicylic acid (the drug in medicines like “Aspirin”) or acetaminophen (paracetamol), are available over-the-counter.
  • Opioid painkillers mainly affect the central nervous system (brain and spinal cord), where pain signals from the other nerves arrive and are processed. These drugs are only used to treat moderate to severe pain and they are prescription-only. Examples of opioids include oxycodone or tramadol.

Nerve pain can be treated with a combination of non-opioid and opioid painkillers.

Sometimes antidepressants or anticonvulsants are used too. Lidocaine or capsaicin skin patches are sometimes recommended as well. Studies suggest that capsaicin patches with 8% capsaicin can relieve the nerve pain. There haven’t been enough good-quality studies to tell whether the other treatments can noticeably reduce the pain.

If you need long-term pain therapy it may be a good idea to see a specialized pain therapist or contact a pain center or pain clinic.

Antidepressants

Amitriptyline and duloxetine are the two main antidepressants prescribed for post-herpetic neuralgia.

You’ll usually be started on a low dose, which may be increased depending on the benefits and side effects. It may take a few weeks to feel the full effects.

Common side effects include a dry mouth, constipation, dizziness and drowsiness. Not everyone gets side effects.

If these medications still don’t help after several weeks, or if they’re causing significant side effects, your dose will need to be gradually reduced to prevent withdrawal effects.

Anticonvulsants

Gabapentin and pregabalin are the two main anticonvulsants prescribed for post-herpetic neuralgia.

Antiepileptic medications such as carbamazepine, phenytoin [phenytoin], gabapentin and pregabalin have been proven to be efficacious in treating postherpetic neuralgia pain, aiding in ability to sleep and improving quality of life. The drawbacks of antiepileptic medication are the heavy side effects such as headache, dizziness and sleepiness, which are especially disconcerting in the elderly.

Perhaps the best studied are gabapentin and pregabalin which are thought to act specifically in the spinal cord.

Like the antidepressants used for post-herpetic neuralgia, they should be started at a low dose, which is gradually increased over a few days or weeks. They also usually need to be taken for a few weeks before they start to take effect.

Not everyone gets side effects when taking gabapentin and pregabalin. Possible side effects can include dizziness, drowsiness, poor memory, increased appetite and weight gain.

If these medications still don’t help after several weeks, or if they’re causing significant side effects, your dose will need to be gradually reduced.

Other treatments

If your pain gets worse despite treatment, you may be referred to a specialist pain clinic. While waiting for your appointment, you might be offered a medication called tramadol.

Tramadol can be addictive if taken for long periods, so it should be prescribed for the shortest time possible and stopped if it doesn’t help.

If other medications haven’t helped, stronger painkillers, such as morphine-based medications, may be recommended. These can be started by a doctor but may need to be reviewed by a pain specialist. If these medications don’t help, they should be stopped.

Steroid injections

Steroids are sometimes injected into the spine (intrathecal) for postherpetic neuralgia. However, evidence of effectiveness is inconsistent. A low risk of serious side effects, including meningitis, has been associated with their use.

Spinal cord stimulation

If all other options have not been successful, spinal cord stimulation has recently been used for treating postherpetic neuralgia. It has not yet been extensively studied, but results to date have shown that up to 82% of people received pain relief after experiencing pain from postherpetic neuralgia for up to 2 years.

Living with post-herpetic neuralgia

Living with post-herpetic neuralgia can be very difficult because it can affect your ability to carry out simple daily activities, such as dressing and bathing. It can also lead to further problems, including extreme tiredness, sleeping difficulties and depression.

Lifestyle and psychology

A lifestyle change can make a big difference to treatment success and managing pain in postherpetic neuralgia. Lifestyle changes that may help people with postherpetic neuralgia include:

  • Avoiding activities, situations and clothing that exacerbate the pain;
  • Learning how to manage the condition and how to cope with the pain and side effects of the treatment;
  • Improving positive outlook by adopting a healthier lifestyle, which also benefits physical and psychological profile; and
  • Modifying thinking patterns in order to reduce stress and anxiety through help with psychotherapy programs such as cognitive behavioural therapy.

A better approach to reducing pain is a combination of:

  • exercise
  • staying at work
  • physical therapy
  • painkillers

Exercise to beat pain

Choose an exercise that won’t put too much strain on yourself. Good options include:

  • walking
  • swimming
  • exercise bike
  • dance/yoga/pilates
  • most daily activities and hobbies

Activity and stretching needs to become part of your lifestyle so you routinely do exercise little and often.

Try to be active every day, instead of only on the good days when you’re not in so much pain. This may reduce the number of bad days you have and help you feel more in control.

But try and avoid overdoing it on good days and then paying for this by having more and more bad days.

Go to work despite the pain

It’s important to try to stay in work even though you’re in pain. Research shows that people become less active and more depressed when they don’t work.

Being at work will distract you from the pain and won’t make your pain worse.

Talk to your supervisor or boss about the parts of your job that may be difficult to begin with, but stress that you want to be at work.

If you have to stay off work for a while, try to get back as soon as possible.

If you’ve been off work for four to six weeks, plan with your doctor, therapist or employer how and when you can return.

You could go back to work gradually. For instance, you might start with one day a week and gradually increase the time you spend at work.

You could also agree changes to your job or pattern of work, if it helps – a health and safety rep or occupational health department may be useful here.

Postherpetic neuralgia natural treatment

Pain experts often recommend a short course of physical therapy.

This helps you to move better, relieves your pain, and makes daily tasks and activities, such as walking, going up stairs, or getting in and out of bed, easier.

Physical therapy for persistent pain can involve manipulation, stretching exercises and pain relief exercises.

Physical therapy is usually delivered by an osteopath, chiropractor or a physiotherapist.

Acupuncture is also offered across the US by some healthcare providers, including physiotherapists, especially for back pain and neck pain.

Physiotherapists can give you advice on the right type of exercise and activity.

Occupational therapists can support you with environmental changes that can help you remain in work and function better at home.

If you have physical therapy, you should begin to feel the benefits after a few sessions.

Meditation for pain

This free 20 minute guided meditation course from Meditainment (https://www.meditainment.com) is easy-to-follow, free and proven to help people cope with chronic pain.