Shingles is caused by the herpes zoster virus, the same virus that is responsible for chicken pox infection. Even though a chicken pox infection will resolve, the herpes zoster virus remains in a person's nervous system for the rest of their life. The virus usually hibernates in the spinal cord, and when a person's immune system is weakened, the virus can be reactivated. According to the National Institutes of Health (NIH), individuals who have had chicken pox have a one in five chance of developing shingles as an adult.
Typical Disease Course
Shingles outbreaks run a similar course to a chicken pox infection. During the first two to three days, people may feel tired and feverish. These symptoms are followed by development of a localized area of skin irritation. A tingling, itching or painful burning sensation will develop, most commonly on the upper body. However, shingles can develop on the extremities and face as well. The hallmark indicator of shingles is unilateral symptoms (one side of the body is affected). This is because the virus follows a specific nerve path, or dermatome, beginning in the spine and following the dermatome to the surface of the skin.
The next phase of a shingles infection is a one-to-two-week period of blistering rash development. This rash is similar to chicken pox and can take seven to 14 days to scab over. Typically, another one to two weeks are needed for the lesions to completely heal.
A simple course of shingles can last anywhere from one month to several months. The severity and duration of the infection are dependent on the age and health of the affected person. According to the NIH, age and physical and emotional stress can weaken a person's immune system, making them more susceptible to prolonged shingles outbreaks.
According to neurologist Dr. Hana Aubrechtova with the Austin Neurological Clinic, shingles can cause serious chronic complications. A condition called post-herpetic neuralgia can occur, resulting in protracted pain. People with this development report hypersensitivity to the skin in the affected area. Very light touch to the area can cause severe pain and burning. The simple contact of clothing on skin can become intolerable. These symptoms may never resolve.
Dr. Aubrechtova states that the virus may travel along different cranial nerves with the potential to cause permanent damage to those nerves. For example, if the trigeminal nerve is affected, the result could be severe shooting facial pain and numbness. rarely, the cornea could be affected by ulceration and subsequent visual impairment.
According to the Centers for Disease Control, two potentially life-threatening complications of shingles are pneumonia and encephalitis, or brain inflammation. Another serious complication of shingles outbreak is a development of secondary infection in the rash.