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Shingles

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Shingles, also known as herpes zoster or zona, is a viral disease. It is characterized by a painful skin rash that forms blisters in a specific area.

Shingles
Shingles

This rash typically appears as a single, wide mark. It usually stays on the left or right side of the body or face. This pattern is called a dermatomal distribution because it follows a specific nerve path.

Herpes zoster chest
Herpes zoster chest

The disease is caused by the varicella zoster virus (VZV). This is a double-stranded DNA virus. It belongs to the alpha subfamily of herpesviruses. While it is related to the herpes simplex virus, they are not the same.

The mechanism of shingles begins with a previous infection. Most people are first infected with VZV during childhood or adolescence. This initial infection causes chickenpox, also called varicella. After the chickenpox resolves, the virus does not leave the body. Instead, it remains dormant, or latent, in human nerve cells. These cells are located in the dorsal root ganglia near the spinal cord or the trigeminal ganglion in the skull.

Varicella (Chickenpox) Virus PHIL 1878 lores
Varicella (Chickenpox) Virus PHIL 1878 lores

The virus stays inactive for many years or even decades. Scientists are still studying exactly why the virus suddenly reactivates after being dormant.

When the virus reactivates, it follows a specific biological path. The virus particles begin to replicate within the neuronal cell bodies. These virions are then shed from the cells. They travel down the axons toward the nerve endings in the skin.

A Course of Shingles diagram
A Course of Shingles diagram

This movement causes local inflammation and the formation of blisters. The pain from shingles comes from the inflammation of the affected nerves. This happens because the virus grows widely in those specific areas. The rash often starts with sensations like burning, itching, or tingling. Some people experience hyperesthesia, which is an oversensitivity to touch. Others feel paresthesia, which is a sensation of pins and needles.

The progression of the rash follows distinct stages. First, the skin may show small bumps that look like hives.

ShinglesDay1
ShinglesDay1

Within one to three weeks, the rash becomes vesicular. This means it forms small blisters filled with a serous exudate, or clear fluid.

ShinglesDay2 ed
ShinglesDay2 ed

These vesicles eventually become cloudy or dark as they fill with blood. Within seven to ten days, the blisters typically crust over.

ShinglesDay5 ed
ShinglesDay5 ed

Most people heal once the crusts fall off. However, some people may be left with scarring or discolored skin. In rare cases, a person might experience zoster sine herpete, where they have all the symptoms but no rash at all.

Shingles can affect different parts of the body in various ways. If the virus affects the trigeminal nerve, it is called zoster ophthalmicus. This occurs in approximately 10% to 25% of cases. It can involve the forehead, eyelid, and eye, sometimes leading to vision loss.

Herpes zoster ophthalmicus.2
Herpes zoster ophthalmicus.2

Another type is shingles oticus, or Ramsay Hunt syndrome type II. This involves the ear and can cause hearing loss or vertigo. The virus can even appear in the mouth. In the mouth, it causes small blisters that turn into ulcers. These ulcers usually heal within 10 to 14 days. For people with poor immune function, the rash can become disseminated. This means more than 20 lesions appear outside the primary area.

History and medical science have helped us understand this disease better. While the disease has been recognized since ancient times, modern biology has provided more detail. The complete sequence of the viral genome was published in 1986. Today, doctors use several methods to diagnose shingles. They often look for the characteristic dermatomal rash pattern. They can also use laboratory tests, such as looking for VZV-specific IgM antibodies in the blood. The most reliable method is a molecular biology test called polymerase chain reaction (PCR). This test can detect the actual DNA of the virus in a sample from a blister.

The significance of shingles is seen in its impact on the population. It is estimated that about one-third of people will develop shingles in their lives. The risk increases with age. Among healthy individuals, there are 1.2 to 3.4 new cases per 1,000 person-years. For those older than 65, the rate rises to 3.9 to 11.8 per 1,000 person-years. About half of people who reach age 85 will have at least one attack. While the symptoms can be severe, the risk of death is very low. It is estimated at only 0.28 to 0.69 deaths per million people. Some people also suffer from postherpetic neuralgia, which is nerve pain that lasts for months or years.

Prevention and treatment are connected to how the virus works. Vaccines can reduce the risk of shingles by 50% to 90%. Vaccination also helps decrease the severity of the disease and the rate of nerve pain. If shingles occurs, antiviral medications like aciclovir can help. These medicines are most effective if started within 72 hours of the rash appearing. While antivirals reduce the duration of the disease, they may not stop long-term nerve pain. Doctors may also use paracetamol, NSAIDs, or opioids to manage acute pain. Understanding the virus helps us protect people from its effects.

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🖼️ Images & Media (10)
File:Fox Plate XCVI.jpg
Fox Plate XCVI.jpg
File:Shingles.JPG
Shingles.JPG
File:ShinglesDay1.JPG
ShinglesDay1.JPG
File:ShinglesDay2 ed.JPG
ShinglesDay2 ed.JPG
File:ShinglesDay5 ed.JPG
ShinglesDay5 ed.JPG
File:ShinglesDay6 ed.JPG
ShinglesDay6 ed.JPG
File:Varicella (Chickenpox) Virus PHIL 1878 lores.jpg
Varicella (Chickenpox) Virus PHIL 1878 lores.jpg
File:A Course of Shingles diagram.png
A Course of Shingles diagram.png
File:Herpes zoster chest.png
Herpes zoster chest.png
File:Herpes zoster ophthalmicus.2.jpg
Herpes zoster ophthalmicus.2.jpg
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