Shingles is a viral nerve infection that causes a painful rash and blistering on the skin. In some cases, the infection can spread to internal organs and can sometimes appear without a rash. Doctors refer to this as internal shingles.
About 1 in 3 people in the United States will develop shingles during their lifetime.
Shingles, or herpes zoster, usually clears up in 2 to 4 weeks. However, as the infection can spread to other organs, it may lead to serious and potentially life-threatening complications if left untreated.
In this article, we look at the causes, symptoms, and complications of internal shingles, as well as treatment and prevention.
Internal shingles
Internal shingles can cause serious complications if left untreated.
Shingles usually causes a painful, itchy, blistering rash. Shingles with no rash is called zoster sine herpete (ZSH), and may cause the following symptoms:
- Chills
- Pain
- Muscle aches
- Numbness and tingling
- Burning under the skin
- Swollen lymph nodes
- Fever
- Headache
The pain from shingles can vary from mild to severe. People may experience sharp, stabbing pains and the affected skin area can feel very tender.
In rare cases, the shingles virus can spread to the internal organs and cause inflammation. Internal shingles can cause the following complications, depending on the organ it affects:
- pneumonia, if it spreads to the lungs
- hepatitis, if it spreads to the liver
- encephalitis in the membranes of the brain
- transverse myelitis in the spinal cord
- problems with the blood vessels
These conditions are all very serious and potentially life-threatening if left untreated. Neurological symptoms that occur outside the rash area require immediate medical attention.
This rash and any itchiness or burning usually occurs in a single band or stripe on one side of the body. It is often located around the waist, chest, stomach, or back.
However, shingles can occur on almost any part of the body, including the face. It can also spread to more than one area.
Other complications
Complications from shingles are more likely to occur in older people or people with weakened immune systems. The following are possible shingles complications:
Postherpetic neuralgia
Following shingles, some people continue to experience nerve pain and intense itching in the area where the rash was. This is known as postherpetic neuralgia (PHN). It is the most common complication of shingles and develops in around 10–13 percent of people who have had shingles.
PHN can persist for months or even years after the other symptoms of shingles have cleared. PHN can be severe, and the pain can be constant or intermittent. In some people, very light touch or changes in temperature can trigger the pain.
PHN can interfere with daily life and can cause depression, anxiety, insomnia, and unintended weight loss.
Ophthalmic shingles
If shingles develops on the face, there is a risk of the eyes being affected. Potential complications involving the eye include:
- Inflammation, causing redness and discharge
- Permanent scarring of the cornea
- Glaucoma or pressure in the eye
- Vision problems
People must get prompt treatment if blisters occur in or around the eyes to avoid the risk of vision loss.
Ramsey Hunt syndrome
Shingles infections near or within the ear can cause Ramsey Hunt syndrome, which leads to hearing or balance problems, dizziness, earache, and paralysis of the face.
Around 75 percent of individuals with Ramsey Hunt syndrome will make a full recovery if they receive antiviral medication with 72 hours of the onset of their symptoms. However, some people may be left with long-term hearing loss or facial paralysis.
What causes internal shingles?
A weakened immune system caused by emotional stress may reactivate the chickenpox virus.
The varicella-zoster virus causes shingles, the same virus that is responsible for chickenpox. Anyone who has had chickenpox can develop shingles later in life. Researchers are not sure why shingles may sometimes appear without a rash.
More than 99 percent of Americans aged 40 years old or more have had chickenpox, usually during childhood.
Following chickenpox, the virus settles in the nervous system near the spinal cord or the base of the skull. There it remains for the rest of a person’s life and is usually kept in check by the immune system.
However, the virus can reactivate at any time. When this occurs, it multiplies and travels along the nerve fibers to the skin, causing symptoms of shingles.
Many internal symptoms may occur before the rash and, in rare cases of ZSH, a rash will never appear.
Doctors do not fully understand why the virus reactivates in some people but not others. However, a weakened immune system is thought to be a contributing factor. This may be caused by:
- Advanced age
- Physical and emotional stress
- Conditions that compromise the immune system, such as HIV and AIDS
- Medications or treatments that suppress the immune system, such as those used in chemotherapy or organ transplantation
People of any age can get shingles, including young children. However, the risk increases significantly with age, and it mostly occurs in people of more than 50 years old.
Diagnosis and treatment
A doctor can prescribe antiviral medications to reduce the symptoms and the risk of developing complications.
A doctor can usually diagnose shingles based on a history of the symptoms and an examination of the rash. In some cases, a skin sample or fluid sample from a blister may be needed.
Shingles without a rash is more difficult to diagnose, and doctors need to do extra tests. One study found that testing a person’s saliva for the virus could diagnose shingles without a rash.
There is no cure for shingles, but antiviral medications can reduce the severity and decrease the risk of developing complications. Antiviral medications should be taken within 72 hours of the rash appearing.
Over-the-counter painkillers, such as acetaminophen and ibuprofen, can be used to relieve the pain, but a doctor can prescribe stronger painkillers if necessary.
People with shingles should keep the rash covered, wear loose-fitting clothes, and avoid scratching or picking the blisters. Applying a cool, damp washcloth may help the blisters dry out faster and ease the pain.
People with shingles can ease their discomfort by:
- Getting plenty of rest
- Trying gentle stretches or walking
- Distracting themselves by reading, watching TV, listening to music, or playing games
- Avoiding stress
- Using calamine lotion or an oatmeal bath to soothe the skin
Is shingles contagious?
People cannot catch shingles from another person but it is possible for someone to catch chickenpox from a person with shingles. This can only happen if someone has not had chickenpox or received the chickenpox vaccine.
The varicella-zoster virus present in shingles blisters can be spread if someone comes into direct contact with the fluid. It remains contagious until the last blister has dried up and scabbed over.
The risk of spreading the virus is low if the rash is kept covered. Individuals with shingles should avoid contact with anyone who has not already had chickenpox. This is particularly important in the following cases:
- Pregnant women
- Babies less than 1 month old
- People living with HIV and AIDS
- People undergoing chemotherapy
- People having bone marrow or organ transplants
People with shingles should also wash their hands often and avoid swimming, contact sports, and sharing towels. If the rash is oozing and cannot be covered, they should also stay home from work or school.