- Risk Factors
- Signs & Symptoms
What is postherpetic neuralgia (PHN)?
Postherpetic neuralgia (PHN) is a condition of recurring or persistent pain in an area of the body that has undergone an outbreak of herpes zoster virus (HZ), also known as the varicella-zoster virus, commonly termed shingles. It usually begins after shingles lesions (blisters) begin to crust over and heal but may occur in some patients who do not produce lesions. Some investigators suggest the pain has to be present for three months to be termed PHN.
What causes postherpetic neuralgia?
Postherpetic neuralgia is thought to be caused by the damage or alteration of nerves that register pain, pressure, and other sensory nerves (for example, touch) that occur when the reactivated HZ viruses travel down nerves to the skin. This process first begins when the virus causes chickenpox in an individual; the viruses can infect various dorsal root ganglia (nerve cells) as chickenpox subsides. These viruses can be reactivated, usually decades later, and produce shingles lesions.
The reactivation of HZ is thought to be due to stress on the body from either another infection or an immunocompromised state (for example, some patients undergoing treatments for leukemia) that allows the HZ to escape the dorsal root cells.
PHN does not occur in everyone who gets shingles.
- About 9%-14% have symptoms after one-month post-shingles
- About 5% have PHN three months post-shingles
What are the risk factors for postherpetic neuralgia?
Age is a high-risk factor for PHN; the older a person is when they develop shingles, the more likely it is that the person will develop PHN.
- People over 60 have about a 60% chance of developing PHN after getting shingles
- People 70 or older have about a 75% chance of developing PHN after getting shingles
Another risk factor is family; people with close relatives who developed PHN are at a higher risk than those with no family history of PHN.
What are symptoms and signs of postherpetic neuralgia?
The main symptom is pain. The pain can be severe (allodynia - pain due to a stimulus that does not usually provoke pain); patients describe the pain as burning, sharp, jabbing, deep, and aching. Often, the patient feels increased pain when any pressure, even clothing, touches the area. Some patients describe itchy skin and weakness or paralysis of the area.
How is postherpetic neuralgia diagnosed?
The majority of patients who are diagnosed with PHN are done by follow-up of a shingles infection or by the patient's history of a recent shingles infection. The pain is located in the same nerve distribution (dermatome) area, usually on only one side of the person's body where the shingles lesions occurred.
What is the treatment for postherpetic neuralgia?
Treatment is individualized for each patient; no treatment is effective for all PHN patients, so clinicians often use two or more of the drug categories with examples listed below:
- Lidocaine skin patches ([Lidoderm] small, bandage-like patches applied to painful areas)
- Capsaicin skin patches ([Capsagel, Salonpas] used in a doctor's office by trained staff)
- Opioids (tramadol [Ultram], oxycodone [OxyContin], morphine)
- Anticonvulsants (pregabalin [Lyrica], gabapentin [Neurontin]) have been shown to lessen the pain of PHN probably by stabilizing abnormal electrical activity in your nervous system.
- Antidepressants (venlafaxine [Effexor], duloxetine [Cymbalta]) are often prescribed in lower doses than for depression.
Because some drugs (opioids) can be addictive and some patients may need long-term treatments (over one year), consultation with a pain-management specialist may be advised. Some individuals claim tamanu oil rubbed into the affected may reduce the symptoms of PHN. One small study and a few case reports indicate that acupuncture can help relieve the pain of PHN. Infrequently, other methods are used. TENS (transcutaneous electrical nerve stimulation) devices are designed to interrupt the body's pain sensations while nerve blocks (short-term chemical nerve sensation blockade) and nerve ablation (surgically cutting a nerve) are also used. Results vary but the methods often do not give lasting pain relief.
How long does postherpetic neuralgia last?
Only approximately 9%-15% of patients who get shingles develop PHN. For those few patients who develop PHN, the length of time that PHN lasts is variable; most PHN patients have discomfort lasting one to two months. About one-third of PHN patients have symptoms that last about three months and about one-fifth last a year or longer.
What is the prognosis for postherpetic neuralgia?
For the majority of patients who develop PHN, the prognosis is good although they may have to take pain medications for about one to three months. For others, the prognosis is fair to poor if the pain is severe, lasts longer than three months, or markedly reduces their quality of life. PHN occasionally results in permanent nerve damage; however, the disease is not fatal.
What are the complications of postherpetic neuralgia?
PHN itself is a complication of shingles. A severe complication of PHN is an addiction to pain medications. Some patients may be unable to live a normal lifestyle (unable to exercise) because of constant pain. In contrast, others have sleep and activities limited or even prohibited by touching the affected area, including just having contact with their clothing. Patients taking opioids may become very constipated. In a few cases of PHN, muscle weakness can be an additional complication.
Is it possible to prevent postherpetic neuralgia?
If shingles can be prevented, then PHN can be prevented. Fortunately, the vaccine Zostavax is about 70% effective in preventing shingles. The CDC recommends that everyone older than 60 years of age get the vaccine; in 2011, the FDA approved the vaccine for people aged 50 and above.
The CDC states, "Zostavax should not be given to pregnant women, persons with a primary or acquired immunodeficiency, or to persons with a history of anaphylactic reaction to gelatin, neomycin, or any other component of the vaccine. Herpes zoster vaccine can be administered simultaneously with other indicated vaccines."
McElveen, W. Alvin. "Postherpetic Neuralgia." Medscape.com. Dec. 1, 2017. <http://emedicine.medscape.com/article/1143066-overview>.
Stone, Jennifer A.M., Gettelfinger, Gary L., and Johnstone, Peter A.S. "Treatment of 13 Patients With Post-Herpetic Neuralgia Using Acupuncture." Journal of the Society for Integrative Oncology 8.4 Fall 2010: 125-130.
United States. Centers for Disease Control and Prevention. "Update on Herpes Zoster Vaccine: Licensure for Persons Aged 50 Through 59 Years." MMWR 60.44 Nov. 11, 2011: 1528. <http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6044a5.htm>.
Top Postherpetic Neuralgia Related Articles
AcupunctureAcupuncture is the practice of inserting needles into the body to reduce pain or induce anesthesia. More broadly, acupuncture is a family of procedures involving the stimulation of anatomical locations on or in the skin by a variety of techniques.
Atopic DermatitisEczema is a general term for many types dermatitis (skin inflammation). Atopic dermatitis is the most common of the many types of eczema. Other types of eczema include: contact eczema, allergic contact eczema, seborrheic eczema, nummular eczema, stasis dermatitis, and dyshidrotic eczema.
Can You Have a Mild Case of Shingles?The severity of shingles depends on various factors, such as age of the patient, general health condition of the patient, and the part of the body where shingles develops.
Chickenpox (Varicella)Chickenpox (chicken pox) is a contagious childhood disease caused by the varicella-zoster virus. Symptoms have an incubation period of 14 to 16 days and include a couple days of mild fever, weakness, and red, raised rash that progresses to blisters that eventually burst and crust over. Complications include bacterial infection of the open sores, scarring, encephalitis, nerve palsies, and Reye's syndrome.
Drug Abuse and AddictionDrug abuse and addiction is a chronic disease that causes drug-seeking behavior and drug use despite negative consequences to the user and those around him. Though the initial decision to use drugs is voluntary, changes in the brain caused by repeated drug abuse can affect a person's self-control and ability to make the right decisions and increase the urge to take drugs. Drug abuse and addiction are preventable.
Itching (Pruritus)Itching can be a common problem. Itches can be localized or generalized. There are many causes of itching including infection (jock itch, vaginal itch), disease (hyperthyroidism, liver or kidney), reactions to drugs, and skin infestations (pubic or body lice). Treatment for itching varies depending on the cause of the itch.
Pain ManagementPain management and treatment can be simple or complex, according to its cause. There are two basic types of pain, nociceptive pain and neuropathic pain. Some causes of neuropathic pain include:
- complex regional pain syndrome,
- interstitial cystitis,
- and irritable bowel syndrome.
Shingles (Herpes Zoster)Shingles, or herpes zoster, is a painful rash caused by the varicella zoster virus. Other shingles symptoms include headache, fever, nausea, and body aches. Treatment focuses on pain management and shortening the duration of the illness with antiviral medications.
Shingles QuizShingles falls within a well-known family of viruses that cause itching, burning, blisters, and pain. Take the Shingles Quiz to get the facts, causes, symptoms, and treatments for this itchy, painful condition.
Shingles PicturesAn acute infection caused by the herpes zoster virus, the same virus as causes chickenpox. See a picture of Shingles and learn more about the health topic.
What Is the Main Cause of Shingles Rash? Signs, Symptoms, VaccineShingles occurs when the varicella-zoster virus, the same virus that causes chickenpox, re-emerges due to a weakened immune system. Tingling may occur before herpes zoster blisters appear, usually on the side of the body. The shingles vaccine can boost the immune system to lower the risk of shingles outbreaks.
Myths and Facts About ShinglesThere are some common misconceptions about this viral illness and the uncomfortable rash it can cause. Here's a guide through the myths and facts of shingles.
Skin Problems: Rosacea, Acne, Shingles, Covid-19 RashesLearn to spot and treat skin conditions commonly found in adults such as acne, Covid-19 rashes, eczema, shingles, psoriasis, rosacea, hives, cold sores, razor bumps, athlete's foot, and more dermatology details.
Transcutaneous Electrical Nerve Stimulation (TENS)Transcutaneous electrical nerve stimulation (TENS) is a technology that uses a small device to deliver electrical current into tissues to help alleviate pain. TENS is helpful in treating various conditions, including:
- chronic neck pain and
- chronic back pain.
What Triggers a Shingles Outbreak?Shingles occur when the varicella-zoster virus, the same virus responsible for chickenpox, reactivates in the body, usually due to a weakened immune system. Learn about the symptoms of shingles and how you can treat them. The difference between chickenpox and shingles is that the first time you get infected with the varicella virus, you get chickenpox. Shingles is a condition you can develop if you've already had chickenpox. Learn about the differences between chickenpox and shingles and how these two diseases are connected.