Saturday, February 6, 2010

The active infection.

A rash appears, starting as well-defined, small, red, clear spots.
Within 12 - 24 hours, these pimples develop into small fluid-filled blisters.
The blisters grow, merge, and become pus-filled.
Pain is common during the active infection.
Within about 7 - 10 days (as with chickenpox), the blisters form crusts and heal. In some cases it may take as long as a month before the skin clears completely. Healing takes even longer in patients who have impaired immune systems, and, in such cases, the blisters may last for months.
Zoster Sine Herpete. Sometimes pain develops without a rash, a condition known as zoster sine herpete. This usually occurs in elderly patients. Symptoms include burning or shooting pain, numbness, tingling, itching, headache, fever, chills, and nausea. An accurate early diagnosis of shingles in such cases is often difficult. Some evidence suggests that some cases of Bell's palsy (in which part of the face becomes paralyzed) might actually be an indication of zoster sine herpete.

Postherpetic Neuralgia. Postherpetic neuralgia (PHN) is pain that persists for longer than a month after the onset of herpes zoster. PHN occurs in about 10 - 20% of patients who have shingles.

A diagnosis may be difficult if herpes zoster takes a non-typical course in the face, such as with Bell's palsy or Ramsay Hunt syndrome, or if it affects the eye or causes fever and delirium.

Typical Shingles (Herpes Zoster).prodrome,active infection,syndrome known as postherpetic neuralgia - (ZAP).

Shingles nearly always occurs in adults. It develops on one side of the body. Usually two, and sometimes three, identifiable symptom stages occur:

The first is known as the prodrome, a cluster of warning symptoms that appear before the outbreak of the infection.
The second stage comprises the symptoms of the active infection itself.
In many patients, a third syndrome known as postherpetic neuralgia later develops.
Pain is so common to all stages of herpes zoster that doctors often refer to all syndromes with a single term: Zoster-Associated Pain (ZAP).

Prodrome (Pain).

Pain is the primary early symptom for shingles, and it occurs in all patients. The pain most often occurs in the skin at the site of the re-activated virus. The pain may be experienced as sharp, aching, piercing, tearing, or similar to an electric shock.
The affected skin may itch, feel numb, and be unbearably sensitive to touch. Often the patient experiences a combination of these sensations along with pain.
In addition, some patients may have flu-like symptoms such as muscle aches. (Some people have fever, but it is uncommon.)
The prodrome stage lasts 1 - 5 days before the infection becomes active and the skin rash erupts. Occasionally, the pain can last weeks or even months before the rash erupts.

Active Shingles. The rash that marks the active infection follows the same track of inflamed nerves as the prodrome pain. Between 50 - 60% of cases occur on the trunk. The second most common site is the head, particularly on one side of the face. It may also erupt on the neck or lower back. If the face is affected, there is a danger that the infection can spread to the eye or mouth. A rash that follows the side of the nose is a warning that the cornea of the eye is in danger.

High-Risk Candidates for Complications of Chickenpox.

Elderly people. The older the patient, the higher the risk for complications from either chickenpox or shingles. Adults who smoke are at particularly higher risk for pneumonia from chickenpox.

Patients with Serious Illnesses. People with serious illnesses may be at risk for complications of the varicella-zoster virus. Patients with diseases, such as Hodgkin's disease, who receive bone marrow or stem cell transplants are at higher risk for herpes zoster and its complications.

Pregnant Women. Pregnant women who become infected with the varicella-zoster virus, whether in the form of chickenpox or shingles, are at increased risk for serious pneumonia.

The risk for the infant is lower or higher depending on when the mother became infected.
Chickenpox in the mother during early pregnancy poses a slightly increased risk for birth defects in the infant.
The highest risk for birth defects is about 2%, which usually occurs if the mother has chickenpox between the 13th and 20th week. Even in such cases, birth defects may only result in minor skin abnormalities. More serious defects include a smaller than normal head, eye problems, low birth weight, and mental retardation.
If women develop chickenpox (not shingles) within 5 days before and 2 days after delivery, their newborns are at risk for life-threatening varicella.
Newborns and Infants. Chickenpox in newborns is a life-threatening condition. Although chickenpox can still be very dangerous in older infants, most are protected by antibodies in breast milk from mothers who have had chickenpox. Children under age 1 who develop chickenpox are at higher risk for childhood shingles. All infants should have as little exposure as possible to people with chickenpox.

Complications of Shingles (Herpes Zoster).The pain and discomfort of the active herpes zoster infection.Effects on Face and Ears.The following are ri

Pain. The pain and discomfort of the active herpes zoster infection is the primary symptom and complication of herpes zoster. The pain usually takes one of these forms:

Continuous burning or aching pain
Periodic piercing pain
Spasm similar to electric shock
Such experiences may also be more intense than even normal responses, defined in the following ways:

Allodynia is pain caused by factors, such as a light touch of clothing or a cold wind, which occurs from very little stimulation.
Hyperalgesia is a more intense painful response to a normally painful experience.
The pain tends to be more severe at night. Temperature changes can also affect pain. The pain may extend beyond the areas of the initial zoster attack. In most cases, it does not affect daily life. Rarely, however, the pain of herpes zoster affects sleep, mood, work, and overall quality of life. This can lead to fatigue, loss of appetite, depression, social withdrawal, and impaired daily functioning.

Itching. Many patients report itching (postherpetic itch) as the primary symptom, rather than pain. In rare cases, it can be disabling.

Postherpetic Neuralgia (PHN). Postherpetic neuralgia (PHN) is pain that persists for longer than a month after the onset of herpes. It is the most common severe complication of shingles. It is not clear why PHN occurs. Some theories for its development are:

The herpes zoster virus appears to produce persistent inflammation in the spinal cord that causes long-term damage, including nerve scarring.
Nerves that are injured in the initial attack may heal abnormally and provoke an exaggerated response in the brain that produces intense sensitivity or pain.
In people with herpes zoster, the risk of developing PHN ranges from 10 - 70%. In general, however, the risk is likely to be in the lower range. People with impaired immune systems do not seem to be at any higher risk for persistent PHN than those with normal immune systems.

The following are risk factors for PHN:

Age. PHN affects about 25% of herpes zoster patients over 60 years old. The older a person is, the longer PHN is likely to last. It rarely occurs in people under age 50.
Gender. Some studies suggest that women may be at slightly higher risk for PHN than men.
Severe or Complicated Shingles. People who had prodromal symptoms or a severe attack (numerous blisters and severe pain) during the initial shingles episode are also at high risk for PHN. The rate is also higher in people whose eyes have been affected by zoster.
In most cases, PHN resolves within 3 months. Some doctors define persistent pain after a herpes zoster attack as subacute herpetic neuralgia if it lasts between 1 - 3 months and as PHN only if it lasts beyond 3 months. Studies report that only about 10% of patients experience pain after a year. Unfortunately, when PHN is severe and treatments have not been very effective, the persistent pain and abnormal sensations can be profoundly frustrating and depressing for patients.

Secondary Infection in the Blisters. If the blistered area is not kept clean and free from irritation, it may become infected with group A Streptococcus or Staphylococcus bacteria. If the infection is severe, scarring can occur.

Guillain-Barre Syndrome. Guillain-Barre syndrome is caused by inflammation of the nerves and has been associated with a number of viruses, including herpes zoster. The arms and legs become weak, painful, and, sometimes, even paralyzed. The trunk and face may be affected. Symptoms vary from mild to severe enough to require hospitalization. The disorder resolves in a few weeks to months. Other herpes viruses (cytomegalovirus and Epstein-Barr), or bacteria (Campylobacter) may have a stronger association with this syndrome than herpes zoster.

Effects on Face and Ears.

Ramsay Hunt Syndrome. Ramsay Hunt syndrome occurs when herpes zoster causes facial paralysis and rash on the ear (herpes zoster oticus) or in the mouth. Symptoms include severe ear pain and hearing loss, ringing in the ear, loss of taste, nausea, vomiting, and dizziness. Ramsay Hunt syndrome may also cause a mild inflammation in the brain. The dizziness may last for a few days, or even weeks, but usually resolves. Severity of hearing loss varies from partial to total; however, this too usually always goes away. Facial paralysis, on the other hand, may be permanent.
Bell's Palsy. Bell's palsy is partial paralysis of the face. There is some indication that this syndrome may suggest a reactivation of herpes zoster, even if no rash appears.
Sometimes, it is difficult to distinguish between Bell's palsy and Ramsay Hunt syndrome, particularly in the early stages. In general, Ramsay Hunt syndrome tends to be more severe than Bell's palsy.
Effects on the Brain. Inflammation of the membrane around the brain (meningitis) or in the brain itself (encephalitis) is a rare complication in people with herpes zoster. The encephalitis is generally mild and resolves in a short period. In rare cases, particularly in patients with impaired immune systems, it can be severe and even life threatening.

Reye Syndrome.Other Rare Complications of Chickenpox

Reye Syndrome. Reye syndrome, a disorder that causes sudden and dangerous liver and brain damage, is a side effect of aspirin therapy in children who have chickenpox or influenza. The disease can lead to coma and is life threatening. Symptoms include rash, vomiting, and confusion beginning about a week after the onset of the disease. Because of the strong warnings against children taking aspirin, this condition is, fortunately, very rare. Children should never be given aspirin when they have a viral infection or fever. Acetaminophen (Tylenol) is the preferred drug for fever or pain in patients younger than age 18 years.

Other Rare Complications of Chickenpox. Other extremely rare complications of varicella include problems in blood clotting and inflammation of the nerves in the hands and feet. Inflammation can also occur in other areas of the body, such as the heart, testicles, liver, joints, or kidney.

Disseminated Varicella

Disseminated Varicella. Disseminated varicella, which develops when the virus spreads to organs in the body, is extremely serious and is a major problem for patients with compromised immune systems. An immune system may become compromised as a result of diseases such as AIDS, inherited conditions, or certain drugs. For example, disseminated varicella occurs in up to 35% of children with chickenpox who are undergoing cancer chemotherapy. In such cases, mortality rates are between 7 - 30%.

Effects During Pregnancy

Effects During Pregnancy. The risk for chickenpox in a pregnant woman is very low (1 - 7 cases in 10,000). However, chickenpox places the woman at risk for life-threatening pneumonia. Infection in the pregnant woman in the first trimester also poses a 1 - 2% chance for infecting the developing fetus, which is an extremely serious condition. (Herpes zoster is even rarer in pregnant women, and there is almost no risk for the unborn child in such cases.)