Post Herpetic Neuralgia

What Is Post Herpetic Neuralgia?

Post herpetic neuralgia is a type of neuropathic pain that is caused by complications related to the herpes zoster virus, which is the virus that causes chickenpox in children and shingles in adults. Prevalence rates have estimated that between 10-18% of individuals who have ever developed herpes zoster will experience post herpetic neuralgia.

Since the emergence of the chickenpox vaccine, some studies have suggested that the risk for developing post herpetic neuralgia is reduced by nearly 70%. Interestingly, even older adults can benefit from a reduced risk of post herpetic neuralgia by receiving the vaccine.

shingles virusThe development of symptoms associated with post herpetic neuralgia typically occurs in a focused area, near the original outbreak of the herpes zoster virus. In some cases, symptoms and pain may spread to other areas of the body. Specifically, once the original outbreak of the herpes zoster virus resolves, symptoms of pain that persist for three months or more are classified as post herpetic neuralgia.

Symptoms of pain associated with post herpetic neuralgia can range in severity and quality. The pain may also be associated with disrupted sensory feedback throughout the body. More specifically, patients may complain of hypersensitivities in certain areas or even decreased sensation. It is not uncommon for individuals with post herpetic neuralgia to complain of intolerance to the contact of even soft and light clothing. Though quite rare, some patients may report symptoms of muscle tremor, muscle weakness, or even paralysis in cases where motor nerves are affected.

Causes Of Post Herpetic Neuralgia

While the specific mechanisms underlying post herpetic neuralgia are not well understood, the condition generally develops following an outbreak of the herpes zoster virus.

Must Watch Video – What is Post Herpetic Neuralgia?

The original outbreak of the virus is typically characterized by a fever, headache, burning or tingling pain (i.e., sensation of pins and needles), itching, oversensitivity, rash, and small blisters. For many individuals, these symptoms will resolve within several weeks of the original outbreak. In some instances, however, the neuropathic pain will persist for several months and is then classified as post herpetic neuralgia.

Typically, an individual will contract the herpes zoster virus, or chickenpox, during childhood and, as a result, develop a natural immunity that prevents the individual from suffering any additional outbreaks during adulthood. While the body has developed immunity, the virus itself remains dormant inside the body. Thus, there is some risk for the virus to reactivate during a period of time when the body’s immune system is compromised.

Herpes zosterFor example, when individuals are under high degrees of stress or are taking certain kinds of medication that suppress the body’s immune system, they are at an increased risk for developing symptoms of shingles. Since the individual had already developed immunity to the virus during the original outbreak, it is likely that they will not suffer from a fully blown attack. It is common for these individuals to develop a smaller outbreak characterized by a rash, pain, and discomfort. Further, this less severe outbreak is typically localized to one specific area (generally the area of original outbreak).

The pain and other symptoms associated with post herpetic neuralgia are thought to emerge as the result of damage sustained to nerve fibers following an outbreak of the virus. Nerves that are irritated or injured as a result of the outbreak send exaggerated signals of pain to the spinal cord and brain. In some cases, the pain and associated symptoms can be so severe that it begins to interfere with the individual’s daily functioning. More specifically, they may experience disturbance in their sleep and appetite. Further, their symptoms may cause them to miss work. In general, the symptoms associated with post herpetic neuralgia tend to remit over time.

Currently, there is no known cure for post herpetic neuralgia. Vaccines have been documented to lower the risk of developing complications related to an outbreak, even among older individuals.

Treatments For Post Herpetic Neuralgia

While there is no cure for post herpetic neuralgia, there are several treatment options available to treat the pain and associated symptoms of the condition.

There are a number of topical agents available to provide relief from symptoms associated with the rash. For instance, your doctor may prescribe lidocaine skin patches. These are small patches that are infused with lidocaine, which is a topical, pain-relieving medication. Similarly, capsaicin skin patches may be used to relieve neuropathic pain, as capsaicin has known pain-blocking properties. These topical skin patches may be used for pain relief for anywhere from four to 12 hours.

opioids-300x200For some, non-steroidal anti-inflammatory drugs (NSAIDs) may provide pain relief. Anticonvulsants, in particular, (such as gabapentin) have received some support for their role in relieving neuropathic pain. These medications can be particularly effective in relieving the burning sensations that tend to accompany post herpetic neuralgia pain. Further, antidepressants may be prescribed as they alter the various chemicals within the body that control how pain sensations are interpreted. While this specific type of medication generally does not fully relieve the pain, they tend to be particularly effective in relieving deep, aching types of pain.

In more moderate to severe instances of post herpetic neuralgia, opioids may be indicated to provide more potent pain relief. These medications are highly effective; however, patients who are prescribed opioids must be closely monitored as they run the risk of misuse, addiction, and even possible overdose.

Tens UnitThough rare, some individuals suffer from chronic and unremitting neuropathic pain symptoms. In these instances, the patient may be a good candidate for a transcutaneous electrical nerve stimulation (TENS) unit. This device uses a very mild electrical stimulation of the peripheral nerve endings through the surface of the skin. Similarly, the spinal cord stimulator utilizes electrical stimulation of the spinal column to block the transmission of pain information from the peripheral nerves to the spinal cord and brain.

There are other forms of treatment that may be beneficial when employed as an augment to other treatment. These interventions include:

  • Relaxation practice
  • Acupuncture
  • Heat therapy
  • Cold therapy
  • Moxibustion

Conclusion

Post herpetic neuralgia is a neuropathic pain condition that is associated with the herpes zoster virus. It is common to contract this virus during childhood in the form of chickenpox. Though the body then develops immunity, the virus itself remains dormant within the body and presents a risk for reemergence, particularly during periods of elevated stress or suppressed immune function.

There is no cure for post herpetic neuralgia. Several treatment options are available for managing the symptoms of pain associated with post herpetic neuralgia. Individuals are encouraged to speak with their doctor about treatment options that are right for them.

References

  1. Barbarisi M, Pace MC, Passavanti MB, Maisto M, Mazzariello L, Pota V, Aurillo C. Pregabalin and transcutaneous electrical nerve stimulation for postherpetic neuralgia treatment. Clin J Pain. 2010;26(7):567-72.
  2. Derry S. Sven-Rice A, Cole P, Tan T, Moore RA. Topical capsaicin (high concentration) for chronic neuropathic pain in adults. Cochrane Database Syst Rev. 2013;28.
  3. Gan EY, Tian EA, Tey HL. Management of herpes zoster and post-herpetic neuralgia. Am J Clin Dermatol. 2013;14(2):77-85.
  4. Han Y, Zhang J, Chen N, He L, Zhou M, Zhu C. Corticosteroids for preventing postherpetic neuralgia. Cochrane Database Syst Rev. 2013;28.
  5. Harden RN, Kaye AD, Kintanar T, Argoff CE. Evidence-based guidance for the management of postherpetic neuralgia in primary care. Postgrad Med. 2013;125(4):191-202.
  6. O’Connor KM, Paauw DS. Herpes zoster. Med Clin North Am. 2013;97(4):503-22.

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