Shingles is medically known as Herpes Zoster. This disease is caused by the reactivation of the varicella zoster virus which caused chicken pox. This viral disease is characterized by painful skin rash with blisters in a localized area on one side of the body. This skin rash often comes in stripes.
Reactivation of Chickenpox
Once an episode of chickenpox is resolved, the virus stays inside the body and can be dormant for years. This dormant virus can become active and cause shingles.
The dormant virus commonly stays in the nerve cell bodies and less frequently in areas such as the cranial nerve, autonomic ganglion, and non-neuronal satellite cells of dorsal root. This latent infection may not cause any symptoms until years or decades before it can reactivate. The virus breaks out of the nerve cell bodies and travels to the axon to cause viral infection of the skin where a particular affected axon is located.
The virus can spread along the nerve of an affected segment leading to an infection of a dermatome. Dermatome is an area of the skin where a particular spinal nerve is located. This infection causes the painful rash of shingles. The rash usually heals within two to four weeks but some cases have been reported that pain lingers for months or years. These cases are called postherpetic neuralgia.
Researchers do not know why the virus stays in the body to become dormant and how it reactivates. One out of five cases of chickenpox may experience Shingles. This condition mainly affects older adults usually above 60 years of age. Rarely does it occur in younger people and children.
The earliest manifestations of shingles are fever, headache, and body weakness. These non-specific symptoms are followed by: sensations of itching, burning pain, stinging, tingling, numbing, oversensitivity, and deep “lightning bolt” pain.
The pain is followed by a rash after 1 to 3 days. Some cases of herpes zoster (shingles) can experience 3 weeks of pain before the rash appears. The rash commonly appears on the torso but it can also appear in areas of the eyes, face, and other parts of the body. Rashes can sometimes be mistaken as hives, but unlike hives, shingles cause skin changes along a specific area of the skin (dermatome).
These rashes form into a stripe or belt-like pattern that is limited only to one side of the body. These are followed by painful red bumps and blisters that erupt and form into pus-filled lesions.
When these lesions resolve, scabs may form within 10 to 12 days. These scabs will fall off within two to three weeks and may cause scarring.
About 15% of shingles cases experience postherpetic neuralgia (the nerve pain). Shingles in children are not painful.
Antiviral medications are given such as acyclovir, valaciclovir and famciclovir. These medications disrupt the viral replication and reduce the severity of the disease.
A seven-to-ten day treatment is to be started within 72 hours of the manifestation of rash.
Analgesics are also given to relieve the agonizing pain of the rash. Morphine, lidocaine, and nerve blocks are also used in cases of severe pain. Gabapentin along with the use of antiviral have been proven to reduce the incidence of postherpetic neuralgia. Steroids are also used together with antivirals because it has been proven to improve the condition faster.
A live vaccine is available to prevent occurrence of shingles. Vaccination has been proven to reduce the number of shingles cases. Older adults are highly advised to have a shot of this vaccine to prevent shingles since they are the most susceptible age group.