Topic Overview
What is shingles?
Shingles (herpes zoster) is a
viral infection of the
nerve roots. It causes pain and often causes a
rash on one side of the body, the left or right. The
rash appears in a band, a strip, or a small area. Shingles is most common in
older adults and people who have weak immune systems because of stress, injury,
certain medicines, or other reasons. Most people who get shingles will get
better and will not get it again.
What causes shingles?
Shingles occurs when the
virus that causes
chickenpox starts up again in your body. After you get
better from chickenpox, the virus ”sleeps” (is dormant) in your nerve roots. In
some people, it stays dormant forever. In others, the virus “wakes up” when
disease, stress, or aging weakens the
immune system. It is not clear why this happens. But
after the virus becomes active again, it can only cause shingles, not
chickenpox.
You can't catch shingles from someone else who has
shingles. But a person with a shingles rash can spread chickenpox to another
person who hasn't had chickenpox and who hasn't gotten the chickenpox
vaccine.
What are the symptoms?
Shingles symptoms happen in
stages. At first you may have a headache or be sensitive to light. You may also
feel like you have the flu but not have a fever.
Later, you may
feel itching, tingling, or pain in a certain area. That’s where a band, strip,
or small area of rash may occur a few days later. The rash turns into clusters
of blisters. The blisters fill with fluid and then crust over. It takes 2 to 4
weeks for the blisters to heal, and they may leave scars. Some people only get
a mild rash, and some do not get a rash at all.
It’s possible that
you could also feel dizzy or weak, or you could have long-term pain or a rash
on your face, changes in your vision, changes in how well you can think, or a
rash that spreads. If you have any of these problems from shingles, call your
doctor right away.
How is shingles treated?
There is no cure for
shingles, but treatment may help you get well sooner
and prevent other problems. Call your doctor as soon as you think you may have
shingles. The sooner you start treatment, the better it works. Treatment may
include:
- Antiviral medicines to help you get well
sooner and feel less pain.
- Medicines to help long-term pain. These include
antidepressants, pain medicines, and skin creams.
Good home care can help you feel better faster. Take care
of any skin sores, and keep them clean. Take your medicines as directed. And
use over-the-counter pain medicines to relieve pain.
Avoid contact
with people until the rash heals. While you have shingles, you can spread
chickenpox to people who have never had chickenpox and who haven't gotten the
chickenpox vaccine. Be extra careful to avoid people with
weak immune systems and pregnant women and babies who
have never had chickenpox and have never gotten the vaccine.
Who gets shingles?
Anyone who has had chickenpox
can get shingles. You have a greater chance of getting shingles if you:3
- Are older than 50.
- Have an
autoimmune disease that causes your immune system to
attack your body’s own tissues.
- Have another health problem or
stress that weakens the immune system.
If you have never had chickenpox and have not gotten the
chickenpox vaccine, avoid touching someone who has shingles or chickenpox. If
you are at least 60 years old, you can get a vaccine that may prevent shingles
or make it less painful if you do get it.
Frequently Asked Questions
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Being diagnosed:
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Getting treatment:
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Ongoing concerns:
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Cause
Shingles
is a
reactivation of the varicella-zoster virus, a type of herpes virus that causes
chickenpox. After you have had chickenpox, the virus
lies inactive in your
nerve roots and remains inactive until, in some
people, it flares up again. When the virus becomes active again, you get
shingles instead of chickenpox.
Anyone who has had even a mild
case of chickenpox can get shingles. People who have a weak
immune system are vulnerable to reactivation of the
virus that causes shingles. Many factors can weaken your immune system,
including aging, injury, and illness. Some medicines slow down the immune
system. For example, medicines that destroy cancer cells (chemotherapy) can interfere with the immune
system.
Transmission
Exposure to shingles will not cause
you to get shingles. But if you have not had chickenpox and have not gotten the
chickenpox vaccine, you can get chickenpox if you are exposed to shingles.
Someone with shingles can expose you to chickenpox if you come into contact
with the fluid in the shingles blisters. If you cover the shingles sores with a
type of dressing that absorbs fluid and protects the sores, you can help
prevent the spread of the virus to other people.
Symptoms
When the virus that causes
chickenpox reactivates, it causes
shingles. Early symptoms of shingles include headache,
sensitivity to light, and flu-like symptoms without a fever. You may then feel
itching, tingling, or pain where a band, strip, or small area of rash may
appear several days or weeks later. A rash can appear anywhere on the body but
will be on only one side of the body, the left or right. The rash will first
form blisters, then scab over, and finally clear up over a few weeks. This band
of pain and rash is the clearest sign of shingles.
The
rash caused by shingles is more painful than itchy.
The
nerve roots that supply sensation to your skin run in
pathways on each side of your body. When the virus becomes reactivated, it
travels up the nerve roots to the area of skin supplied by those specific nerve
roots. This is why the rash can wrap around either the left or right side of
your body, usually from the middle of your back toward your chest. It can also
appear on your face around one eye. It is possible to have more than one area
of rash on your body.
Shingles develops in stages:
Prodromal stage (before the rash appears)
- Pain, burning, tickling, tingling, and/or
numbness occurs in the area around the affected nerves several days or weeks
before a rash appears. The discomfort usually occurs on the chest or back, but
it may occur on the belly, head, face, neck, or one arm or
leg.
- Flu-like symptoms (usually without a fever), such as chills,
stomachache, or diarrhea, may develop just before or along with the start of
the rash.
- Swelling and tenderness of the
lymph nodes may occur.
Active stage (rash and blisters appear)
- A band, strip, or small area of rash appears.
It can appear anywhere on the body but will be on only one side of the body,
the left or right. Blisters will form. Fluid inside the blister is clear at
first but may become cloudy after 3 to 4 days. A few people won't get a rash,
or the rash will be mild.
- A rash may occur on the forehead, cheek, nose, and around one
eye (herpes zoster ophthalmicus), which may threaten your
sight unless you get prompt treatment.4
- Pain, described as “piercing needles in the skin,” may occur
along with the skin rash.
- Blisters may break open, ooze, and crust
over in about 5 days. The rash heals in about 2 to 4 weeks, although some scars
may remain.1
Postherpetic neuralgia (chronic pain stage)
-
Postherpetic neuralgia
is the most
common complication of shingles. It lasts for at least 30 days and may continue
for months to years. Symptoms are:6
- Aching, burning, stabbing pain in the area of the earlier
shingles rash.
- Persistent pain that may linger for
years.
- Extreme sensitivity to touch.
- The pain associated with postherpetic
neuralgia most commonly affects the forehead or chest. This pain may make it
difficult for the person to eat, sleep, and perform daily activities. It may
also lead to
depression.
Shingles may be confused with
other conditions that cause similar symptoms of rash
or pain, such as
herpes simplex infection or
appendicitis.
What Happens
Shingles
is
caused by the same virus that causes
chickenpox. After an attack of chickenpox, the virus
remains in the tissues in your nerves. As you get older, or if you have an
illness or stress that weakens your
immune system, the virus may reappear in the form of
shingles.
You may first have a headache, flu-like symptoms
(usually without a fever), and sensitivity to light, followed by itching,
tingling, or pain in the area where a
rash may develop. The pain usually occurs several days
or weeks before a rash appears on the left or right side of your body. The rash
will be in a band, a strip, or a small area. In 3 to 5 days, the rash turns
into fluid-filled blisters that ooze and crust over. The rash heals in about 2
to 4 weeks, although you may have long-lasting scars.1
A few people won't get a rash, or the rash will be mild.
Most
people who get shingles will not get the disease again.
Complications of shingles
Complications of shingles include:
-
Postherpetic neuralgia
, which is pain
that does not go away within 1 month. It may last for months or even years
after shingles heals. Postherpetic neuralgia affects up to 10% to 15% of those
who experience shingles.2 It is more common in people
age 50 and older and in people who have a weakened immune system due to another
disease, such as
diabetes or
HIV infection. People who have severe pain and rash
during shingles have an increased risk for postherpetic neuralgia.5
-
Disseminated zoster, which is a
blistery rash that spreads over a large portion of the body and can affect the
heart, lungs, liver, pancreas, joints, and intestinal tract. Infection may
spread to nerves that control movement, which may cause temporary
weakness.
- Cranial nerve complications. If shingles affects the
nerves originating in the brain (cranial nerves), complications may include:
- Inflammation,
pain, and loss of feeling in one or both eyes. The infection may threaten your
vision. A rash may appear on the side and tip of the nose (Hutchinson's
sign).
- Intense ear pain, a rash around the ear, mouth, face, neck,
and scalp, and loss of movement in facial nerves (Ramsay Hunt syndrome). Other
symptoms may include hearing loss, dizziness, and ringing in the ears. Loss of
taste and dry mouth and eyes may also occur.
- Inflammation, and
possibly blockage, of blood vessels, which may lead to
stroke.
- Scarring and skin
discoloration.
- Bacterial infection of the
blisters.
- Muscle weakness in the area of the infected skin before,
during, or after the episode of shingles.
What Increases Your Risk
Risks for developing
shingles include:3
If a pregnant woman gets chickenpox, her baby has a high
risk of developing shingles during his or her first 2 years of life.3
Postherpetic neuralgia
is a common
complication of shingles that lasts for at least 30 days and may continue for
months to years. If more than one of the following risk factors is present,
your risk increases for postherpetic neuralgia.5
- Developing shingles after age 50
- Having severe pain
and rash during shingles
- Being female
When To Call a Doctor
Call your doctor immediately if:
- Any sign of
shingles develops (such as pain or changes in vision)
on or in the area of your forehead, nose, eye, or eyelid.
- Any
symptoms of shingles develop (such as headache, stiff neck, dizziness,
weakness, hearing loss, or changes in your thinking and reasoning abilities)
that affect your
central nervous system.
- Skin sores spread
to parts of your body beyond the original area of the
rash.
- You think you have a
bacterial skin infection in the same area as the
shingles rash, or your rash has not healed in 2 to 4 weeks.
- You
develop pain in your face or are unable to move muscles in your face.
Call your doctor today if:
- You suspect you might have shingles. There are
medicines that can limit your pain and rash. The earlier you start treatment
for shingles, the better the results.
Watchful Waiting
If you think you have shingles, see a doctor as soon as possible. Early treatment with
antiviral medicines may help reduce pain and prevent
complications of shingles, such as
disseminated zoster or
postherpetic neuralgia.
If intense pain
persists for more than 1 month after the skin heals, see your doctor to find
out whether you have postherpetic neuralgia.
Who To See
To prepare for your appointment, see the topic Making the Most of Your Appointment.
Exams and Tests
Doctors can usually identify
shingles when they see an area of
rash around the left or right side of your body. If a
diagnosis of shingles is not clear, your doctor may order lab tests, most
commonly
herpes tests, on cells taken from a blister.
If there is reason to think that shingles is present, your doctor may
not wait to perform tests before treating you with antiviral medicines. Early
treatment may help shorten the length of the illness and prevent complications
such as
postherpetic neuralgia.
Treatment Overview
There is no cure for
shingles, but treatment may shorten the length of
illness and prevent complications. Treatment options include:
- Antiviral medicines to reduce the pain and
duration of shingles.
- Pain medicines, antidepressants, and topical creams to relieve
long-term pain.
Initial treatment
As soon as you are diagnosed
with
shingles, your doctor probably will start treatment
with antiviral medicines. If you begin medicines within the first 3 days of
seeing the shingles rash, you have a lower chance of having later
problems, such as
postherpetic neuralgia. Early treatment of shingles is
important, because the problems that can arise can be serious and resistant to
treatment. For example, 40% to 50% of people with postherpetic neuralgia do not
respond to treatment.2
The most common
treatments for shingles include:
-
Antiviral medicines, such as acyclovir,
famciclovir, or valacyclovir, to reduce the pain and the duration of
shingles.
-
Over-the-counter
pain medicines, such
as acetaminophen, aspirin, or ibuprofen, to help reduce pain during an attack
of shingles.
- Topical
antibiotics, applied directly to the skin, to stop
infection of the blisters.
Corticosteroids also may be used to reduce pain in
people younger than 50 who have had a recent outbreak of shingles.
Ongoing treatment
If you have pain that persists
longer than a month after your
shingles rash heals, your doctor may diagnose
postherpetic neuralgia, the most common complication
of shingles. Postherpetic neuralgia can cause pain for months or years. It
affects 10% to 15% of those who experience shingles.2
Treatment to reduce the pain of postherpetic neuralgia includes:2
Topical creams containing
capsaicin may provide some relief from pain. Capsaicin
may irritate or burn the skin of some people, and it should be used with
caution.
Treatment if the condition gets worse
In some
cases,
shingles causes long-term
complications. Treatment depends on the specific
complication.
-
Postherpetic neuralgia
is persistent
pain that lasts months or even years after the shingles rash heals. Certain
medicines, such as anticonvulsants, antidepressants, and opioids, can relieve
pain. Most cases of postherpetic neuralgia resolve within a year. In very rare
cases, surgical treatment may be used to treat postherpetic neuralgia by
cutting nerves to help block pain signals.
- Disseminated zoster is a
blistery rash over a large portion of your body. It may affect your heart,
lungs, liver, pancreas, joints, and intestinal tract. Treatment may include
both antiviral medicines to prevent the virus from multiplying and antibiotics
to stop infection.
-
Herpes zoster ophthalmicus
is a rash on
the forehead, cheek, nose, and around one eye, which could threaten your sight.
You should seek prompt treatment from an
ophthalmologist for this condition.4 Treatment may include rest, cool compresses, and antiviral
medicines.
- If the shingles virus affects the nerves originating in
the brain (cranial nerves), serious complications involving the face, eyes,
nose, and brain can develop. Treatment depends on the nature and location of
the complication.
Prevention
Anyone who has had chickenpox may get
shingles later in life. But there's a vaccine that may
help prevent shingles or make it less painful if you do get it. The
shingles vaccine(What is a PDF document?) is known as Zostavax. One dose is recommended for adults age
60 and older, whether or not they've had shingles before.7
-
Shingles: Should I Get a Shot to Prevent Shingles?
If you have never had
chickenpox, you may avoid getting the virus that
causes both chickenpox and later shingles by receiving the
varicella vaccine.
If you
have never had chickenpox and have never gotten the chickenpox vaccine, avoid
contact with people who have shingles or chickenpox. Fluid from shingles
blisters is contagious. Exposure to this fluid can cause chickenpox (but not
shingles) in people who have never had chickenpox and who have never gotten the
chickenpox vaccine.
If you develop shingles, avoid close contact
with people until after the
rash blisters heal. It is especially important to
avoid contact with people who are at special risk from chickenpox or shingles,
such as:
- Pregnant women, infants, children, or anyone
who has never had chickenpox.
- Anyone who is currently
ill.
- Anyone with a weak
immune system who is unable to fight infection (such
as someone with
HIV infection or
diabetes).
If you cover the shingles sores with a type of dressing
that absorbs fluid and protects the sores, you can help prevent the spread of
the virus to other people.
Home Treatment
You may reduce the duration and pain
of
shingles by:
- Taking good
care of skin sores, such as not scratching blisters and keeping your skin
clean.
- Using medicines as prescribed to treat shingles or
postherpetic neuralgia, which is pain that lasts for
at least 30 days after the shingles rash heals.
- Using
nonprescription pain medicines, such as acetaminophen, aspirin, or ibuprofen,
to help reduce pain during an attack of shingles or pain caused by postherpetic
neuralgia.
If home treatment does not reduce postherpetic neuralgia
pain, talk with your doctor about what you can do to
control the pain.
Medications
Medicines can help limit the pain and
discomfort caused by
shingles, shorten the time you have symptoms, and
prevent the spread of the disease. Medicines also may reduce your chances of
developing shingles
complications, such as
postherpetic neuralgia or disseminated zoster. Early
treatment of shingles is important, because the possible complications can be
serious and resistant to treatment. For example, 40% to 50% of people with
postherpetic neuralgia do not respond to treatment.2
Medication Choices
Medicines to treat shingles when the
rash is present (active stage) may include:
-
Over-the-counter
pain medicines, such as
acetaminophen, aspirin, or ibuprofen, to help reduce pain.
-
Antiviral medicines, to reduce the pain and duration of
shingles.
- Topical
antibiotics, which are applied directly to the skin,
to stop infection of the blisters.
Corticosteroids also may be used to reduce pain in
people younger than 50 who have had a recent outbreak of shingles.
Medicines to treat postherpetic neuralgia pain may include:
-
Over-the-counter
pain medicines, such as
acetaminophen, aspirin, or ibuprofen.
-
Tricyclic antidepressants, such as amitriptyline.
-
Topical medicines, such as a lidocaine patch.
-
Anticonvulsants,
such as gabapentin or pregabalin.
-
Corticosteroids,
such as prednisone.
-
Nerve block injections.
-
Opioids, such as codeine, oxycodone,
and morphine.2
What To Think About
For some people, nonprescription
pain relievers (analgesics) are enough to help control pain caused by shingles
or postherpetic neuralgia.
A prescription medicine called pregabalin (Lyrica) has been
approved for the treatment of pain caused by postherpetic neuralgia. In tests,
it provided rapid and long-lasting pain relief.
Surgery
Surgery for
shingles is quite rare and limited to only the most
severe and prolonged cases of
postherpetic neuralgia, the most common complication
of shingles. Postherpetic neuralgia can be an ongoing and debilitating problem,
especially for older people, but it usually decreases over time. When all other
medical treatments fail to reduce or control pain, you and your doctor may
consider surgical options.
Surgery to relieve postherpetic
neuralgia interrupts the path of pain signals to the brain by cutting nerves in
the skull or spinal column. There are significant risks to this surgery. If
surgery is recommended, it is a good idea to get a second opinion before
proceeding.
Other Treatment
Postherpetic neuralgia
, the most common complication of
shingles, is difficult to treat. Your doctor may
recommend other treatments, along with medicines, to
control the pain of postherpetic neuralgia.
Other Treatment Choices
Other treatments for postherpetic neuralgia
include:
-
Acupuncture, a Chinese therapy that has
been used for centuries to reduce pain.
-
Biofeedback, a method of consciously controlling a
body function that is normally regulated automatically by the
body.
-
Transcutaneous electrical nerve stimulation (TENS)
, a therapy that uses mild electrical current to treat
pain.
- Diathermy, a therapy that uses heat to increase blood flow
for pain relief.
Psychological therapies that help you tolerate long-term
pain may be helpful. These therapies can include counseling and/or relaxation
techniques that teach you to shift your focus of attention away from the pain.
You may want to consider going to a
pain management specialist if you have not found
relief from pain that interferes with your daily living.
What To Think About
It is difficult to assess the
effectiveness of these treatments. Although the pain may last many months or
years, postherpetic neuralgia is usually a self-limiting condition and with
time may heal on its own.
Other Places To Get Help
Organizations
|
National Institute of Neurological Disorders and
Stroke
|
| NIH Neurological Institute |
| P.O. Box 5801 |
| Bethesda, MD 20824 |
| Phone: |
1-800-352-9424 |
| Phone: |
(301) 496-5751 |
| TDD: |
(301) 468-5981 |
| Web Address: |
www.ninds.nih.gov |
| |
|
The National Institute of Neurological Disorders and
Stroke (NINDS), a part of the National Institutes of Health, is the leading
U.S. federal government agency supporting research on brain and nervous system
disorders. It provides the public with educational materials and information
about these disorders.
|
|
|
American Academy of Dermatology
|
| P.O. Box 4014 |
| Schaumburg, IL 60168 |
| Phone: |
1-866-503-SKIN (1-866-503-7546) toll-free
(847) 240-1280 |
| Fax: |
(847) 240-1859 |
| Web Address: |
www.aad.org |
| |
|
The American Academy of Dermatology provides information
about the care of skin, hair, and nails. You can find a dermatologist in your
area by calling 1-888-462-DERM (1-888-462-3376).
|
|
|
American Academy of Family
Physicians
|
| P.O. Box 11210 |
| Shawnee Mission, KS 66207-1210 |
| Web Address: |
www.familydoctor.org |
| |
|
The American Academy of Family Physicians produces a
variety of health-related educational materials. Its Web site offers a health
library and bulletin board, news, and comments sections.
|
|
|
Centers for Disease Control and Prevention (CDC):
Vaccines and Immunizations
|
| 1600 Clifton Road |
| Atlanta, GA 30333 |
| Phone: |
1-800-CDC-INFO (1-800-232-4636) |
| TDD: |
1-888-232-6348 |
| Email: |
cdcinfo@cdc.gov |
| Web Address: |
www.cdc.gov/vaccines |
| |
|
This CDC Web site has information about vaccines and the diseases that can
be prevented by immunization. The Web site includes the recommended
immunization schedules for children, teens, and adults. There is also
information about vaccine side effects and safety, school and state
requirements, and immunization records. Interactive schedules are also
available.
|
|
|
National Institute of Allergy and Infectious Diseases
(NIAID), National Institutes of Health
|
| NIAID Office of Communications and Public Liaison |
| 6610 Rockledge Drive, MSC 6612 |
| Bethesda, MD 20892-6612 |
| Phone: |
1-866-284-4107 toll-free
(301) 496-5717 |
| Fax: |
(301) 402-3573 |
| TDD: |
1-800-877-8339 |
| Web Address: |
www3.niaid.nih.gov |
| |
|
The National Institute of Allergy and Infectious
Diseases conducts research and provides consumer information on infectious and
immune-system-related diseases.
|
|
References
Citations
-
Gnann JW, Whitley RJ (2002). Herpes zoster. New England Journal of Medicine, 347(5): 340–346.
-
Dubinsky RM, et al. (2004). Practice parameter:
Treatment of postherpetic neuralgia. An evidence-based report of the Quality
Standards Subcommittee of the American Academy of Neurology. Neurology, 63(6): 959–965.
-
Whitley RJ (2005). Varicella-zoster virus. In GL
Mandell et al., eds., Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, 6th ed., vol. 2, pp.
1780–1786. Philadelphia: Elsevier/Churchill Livingstone.
-
Barnes SD, et al. (2005). Microbial keratitis. In GL
Mandell et al., eds., Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, 6th ed., vol. 1, pp.
1395–1406. Philadelphia: Elsevier/Churchill Livingstone.
-
Jung BF, et al. (2004). Risk factors for postherpetic
neuralgia in patients with herpes zoster. Neurology,
62(9): 1545–1551.
-
Ashkenazi A, Levin M (2004). Three common neuralgias:
How to manage trigeminal, occipital, and postherpetic pain. Postgraduate Medicine, 116(3): 16–48.
-
Centers for Disease Control and Prevention (2008).
Prevention of herpes zoster: Recommendations of the Advisory Committee on
Immunization Practices (ACIP).
MMWR, 57(05): 1–30. Also available online:
http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5705a1.htm. [Erratum in MMWR, 57(28): 779. Also available online: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5728a5.htm.]
Other Works Consulted
- Gilden DH (2008). Acute viral central nervous system
diseases. In DC Dale, DD Federman, eds., ACP Medicine,
section 11, chap. 16. Hamilton, ON: BC Decker.
- Herpes zoster vaccine (Zostavax) (2006).
Medical Letter on Drugs and Therapeutics, 48(1243):
73–74.
- Johnson RW, Dworkin RH (2003). Treatment of herpes
zoster and postherpetic neuralgia. BMJ, 326(7392):
748–750.
- Katz J, et al. (2004). Acute pain in herpes zoster and
its impact on health-related quality of life. Clinical Infectious Diseases, 39(3): 342–348.
- Pregabalin (Lyrica) for neuropathic pain and epilepsy
(2005). Medical Letter on Drugs and Therapeutics,
47(1217): 75–76.
Credits
|
By
|
Healthwise Staff |
|
Primary Medical Reviewer
|
E. Gregory Thompson, MD - Internal Medicine |
|
Specialist Medical Reviewer
|
Alexander H. Murray, MD, FRCPC - Dermatology |
|
Last Revised
|
May 18, 2010 |
Gnann JW, Whitley RJ (2002). Herpes zoster. New England Journal of Medicine, 347(5): 340–346.
Dubinsky RM, et al. (2004). Practice parameter:
Treatment of postherpetic neuralgia. An evidence-based report of the Quality
Standards Subcommittee of the American Academy of Neurology. Neurology, 63(6): 959–965.
Whitley RJ (2005). Varicella-zoster virus. In GL
Mandell et al., eds., Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, 6th ed., vol. 2, pp.
1780–1786. Philadelphia: Elsevier/Churchill Livingstone.
Barnes SD, et al. (2005). Microbial keratitis. In GL
Mandell et al., eds., Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, 6th ed., vol. 1, pp.
1395–1406. Philadelphia: Elsevier/Churchill Livingstone.
Jung BF, et al. (2004). Risk factors for postherpetic
neuralgia in patients with herpes zoster. Neurology,
62(9): 1545–1551.
Ashkenazi A, Levin M (2004). Three common neuralgias:
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