SHINGLES AND POST HERPETIC NEURALGIA

As a child, you may remember coping with chicken pox—an itchy rash consisting of blisters. Now you have those blisters again, but instead of itching, they are painful. What you are probably experiencing is an outbreak of shingles.

Shingles is an infection caused by a reactivation of the varicella zoster virus, the same virus that causes chicken pox. After the chicken pox blisters have healed, the virus lies dormant (inactive) in neurons (nerve cells) next to your spinal cord, sometimes for decades. When the virus becomes active again, it travels down the nerve fibers that extend to your skin, and a rash develops. The main difference between chicken pox and shingles is that shingles generally erupts in a belt-like pattern on one side of the body, rather than all over your body.

Having had chicken pox—and 90% of Americans over 15 have had it—puts you at risk for getting shingles later on. Two out of every 10 people will get shingles during their lifetime, and more than 1 million people will develop shingles this year.

Many people are unaware that as this virus travels down the nerve fibers it can damage those nerves, sometimes permanently.  And if the damage is severe enough, it can lead to post herpetic neuralgia (PHN), the leading cause of suicide in pain patients over 70 years old.

One in five people with shingles will go on to develop PHN, but the risk increases as you age.  For example, if you are age 50 or older, you have a more than 50 percent chance of developing PHN.  If you are age 80 or older, you have an 80 percent chance of developing PHN. 

PHN SYMPTOMS

The primary symptom is pain, which can be debilitating. The pain may be associated with aching, throbbing, stabbing, sharp, or piercing. Stress may intensify the severity of the pain. The intensity of the pain can vary, but pain-free intervals are rare. Some people who have had PHN describe the pain as the worst pain they have ever felt.

Other symptoms of PHN include itching and burning, and the skin may be very sensitive to changes in temperature (either hot or cold), touch (even from clothing or bedding), or the slightest breeze. People with PHN may also experience muscle weakness, tremor, or paralysis if the nerves that are affected by PHN control muscle movement, but this is rare.

The symptoms of PHN are usually limited to the area of the skin where the shingles rash appeared. However, pain may extend beyond the areas of the original rash.

SHINGLES SYMPTOMS

Though a rash and blisters are symptomatic of shingles, an outbreak may begin without them, so it is important to recognize the other signs and symptoms that accompany the rash.  Unfortunately, these symptoms mimic the flu – fever, headache, chills or nausea.  But other clues can include itching, numbness, tingling, burning pain, or shooting pain on one side of the body or face.  The rash and blisters of shingles almost always occur on just one side of the body, and typically involve the torso, waistline, face, buttocks, arms, or legs.

Usually redness and swelling will appear at the site of the pain, along with clusters of blisters filled with clear fluid.  New blisters will continue to appear for up to 5 days.  These blisters can be scattered in patches or form a continuous band on the skin, and they look a lot like chicken pox.  The  blisters can be mildly irritating, itchy, or intensely painful.  Within 14 days, the blisters become filled with pus and then form a scab.  At this point, they no longer carry the virus.  The rash usually goes away in about 3-5 weeks.  The blisters leave no scars, but you may have discoloration of the skin where they once were.

You cannot catch shingles from someone who has it.  However, if you have not had chicken pox or have not been vaccinated against the varicella zoster virus, you can develop chicken pox if you come in contact with someone who has active shingles with fluid filled blisters. 

PHN DECREASES QUALITY OF LIFE

PHN may last for months, and even years, after the shingles rash has healed. The pain from PHN can have a devastating affect on a person’s life. In some cases, the pain is so severe that all normal daily activity is affected for months, and social isolation can occur. The pain experienced affects every part of a person’s life, and a complete preoccupation with the pain can occur. People with PHN may have trouble sleeping; they may not be able to find a comfortable position sitting, lying down, or even walking around; and they may not want to eat.

Persistent PHN can result in physical, social, and work-related disability. People with PHN may know that their pain will lessen and eventually disappear with time; however, this condition may be accompanied by intense frustration, distress, irritability, and depression.

TREATMENT

The key to treating shingles and PHN is to intervene early.  Both conditions can be treated with oral and topical medications.  But most oral medications can cause significant sedation and dizziness, which is a concern in the elderly population.  Nerve blocks and epidural steroid injections have been used for many years to treat difficult PHN cases.  But there has been recent interest in using these injections to treat active shingles cases – not only to reduce the pain of shingles, but also to reduce the risk of developing PHN down the road.

When the virus leaves the spinal cord and shoots out along nerves, the body’s response appears to be to cut off the “supply lines”, which in this case is the blood flow to the nerve itself.  The result of less blood supply is nerve death.  For this reason, some experts are recommending patients receive nerve blocks and epidural steroid injections in the early phases of shingles in order to improve blood flow and to prevent this from happening.