Risks and Complications of Internal Shingles

Internal shingles, also known as zoster sine herpete (ZSH), is a reactivation of the varicella virus without a rash. This virus is the one that causes chickenpox, and it remains in the body even after that condition resolves.

This reactivation causes shingles, typically characterized by the development of a severe rash. However, internal shingles is particularly concerning because it doesn’t produce this rash. As such, internal shingles cases all too often go untreated, leading to the progression of the disease and serious complications.

Health visitor and a senior woman during nursing home visit - stock photo

FG Trade / Getty Images

Possible complications include nerve pain, inflammation of the brain (encephalitis), vision problems, and Ramsay Hunt syndrome (facial paralysis and other symptoms). These problems arise as the varicella virus spreads to the nervous and other organ systems.

Given the potential severity of internal shingles, it’s important to understand its manifestations and progression. The sooner you’re able to manage and treat this condition, the better off you’ll be.

Symptoms Without Rash

The symptoms of internal shingles are very much dependent on the bodily systems and nerves that the reactivated varicella virus spreads to. As noted, most such relapses produce a characteristic skin rash on one side of the body or face in regular shingles cases, but they don’t do so in internal shingles cases.

Some of the most common symptoms of internal shingles are severe nerve pain and pain and tingling from nerve injury.

Diagnosis

Diagnosis of conditions like internal shingles can be challenging, as many of the characteristic features of other disease manifestations are absent here. This disease is often confused for herpes simplex, scabies, or a host of other conditions, and exact identification of the pathogen is necessary. Current approaches to confirmation of a case include:

  • Symptom assessment: While the characteristic rash isn’t there, doctors may suspect internal shingles in cases of severe nerve pain. While symptoms can’t tell you everything, assessing them is the first step in the diagnosis. Examining medical history—especially records of previous chickenpox and/or shingles cases—is also important.
  • Antibody detection: The body develops antibodies in response to viral attacks. A standard approach to determining the presence of the varicella virus involves clinical testing for these antibodies. Currently, a test called enzyme-linked immunosorbent assay (ELISA) is most often employed.
  • DNA detection with polymerase chain reaction (PCR): This approach involves testing for varicella virus DNA within the cerebrospinal fluid, saliva, or blood. This approach is known to be very sensitive, though there is a relatively higher chance of getting a false positive.

Preherpetic Neuralgia

One of the most striking symptoms of internal shingles is severe pain in the affected nerves. In some regular cases of shingles, this nerve pain (neuralgia) precedes the onset of rash, but in internal shingles, there is no such onset. Since this issue arises without other signs of a flare-up, diagnosis can be delayed.

This pain may be unilateral (occurring on only one side of the body), localized (in a specific area), or radial (occurring on the top of the forearm, wrist, or hand). This sensation can present either as a deeper pain in the joints and muscles or a more surface-focused burning in the skin.

Higher Intensity of Pain With Internal Shingles

While both regular shingles (herpes zoster, or HZ) and internal shingles (ZSH) can cause preherpetic neuralgia, this condition has been found to be more severe in the latter case.

One study found that at the onset of symptoms, after one month, and after three months, internal shingles patients had consistently more severe and persistent pain. Overall, however, preherpetic neuralgia occurs much more frequently in regular herpes zoster patients.

Encephalitis

If viruses spread into the brain and spine, serious issues can arise. Inflammation of the membranes surrounding the spine and brain (meningitis) and inflammation of the brain (encephalitis) are linked to both regular and internal cases of shingles.

This condition causes stiff neck, fever, and headache, with more severe cases leading to mood swings, seizures, and cognitive difficulties. If untreated, these inflammatory conditions can lead to death.

Eye Disorders

If the HZ virus spreads to the eyes, inflammation and damage there severely impact visual ability and can lead to blindness. Internal shingles is particularly associated with progressive outer retinal necrosis (PORN), a rapidly deteriorating condition affecting the retina in the back of the eye.

This leads to rapid reduction in the ability to see, with loss of vision starting at the periphery and moving inward.

Ramsay Hunt Syndrome

This rare disorder is characterized by paralysis of the facial nerve (called palsy) and the development of rashes around the ears and mouth. Palsy causes reduced facial muscle function and can limit the ability to smile or furrow your brow. In addition, the outer ears develop a painful, reddish rash, which can also affect the inside of the mouth.

Other symptoms of this condition, caused by the spread of the varicella virus to the facial nerves and other structures in the head, include:

  • Tinnitus (ringing in the ear)
  • Otalgia (ear pain)
  • Hyperacusis (sounds appearing much louder than normal)
  • Temporary or permanent hearing loss
  • Nausea
  • Vomiting
  • Vertigo (persistent dizziness)

Other Complications

In rarer cases, other complications of internal shingles can emerge, including:

  • Polyneuritis cranialis: This rare, progressive disorder occurs as multiple cranial nerves become affected by varicella virus (though Lyme disease and others can also cause this condition). It’s characterized by confused or interrupted speech, doubling of vision, and inability to swallow, among other symptoms.
  • Cerebellitis: More often seen in children, this is an inflammatory disorder of the brain’s cerebellum that causes fever, headache, or altered mental state or mood. It can also cause neurological symptoms, including tremors, uncontrolled eye movements (nystagmus), speech difficulties (dysarthia), and decreased muscle tone.
  • Circulation problems: Issues with blood circulation can also arise due to internal shingles. In particular, this condition can cause transient ischemic attacks (a type of stroke) and focal deficit (short-term memory loss).
  • Myelopathy: This is severe compression of the spine that arises due to inflammation, some cases of which have been linked to internal shingles progression. This progressive condition can lead to paralysis of the legs and loss of bladder and bowel control, among other symptoms.

A Word From Verywell

Shingles is no less serious, uncomfortable, or painful when it arises without the characteristic rash. What can make this disease dangerous and difficult is allowing the varicella virus to spread unchecked, something that more often happens when you have internal shingles.

The good news is that treatment options are available, with antiviral drugs such as Valtrex (valacyclovir) and Zovirax (acyclovir) leading the charge in taking on internal shingles. In addition, vaccines for the varicella virus are available and work quite well in preventing onset.

Be mindful of how you’re feeling, and if things seem awry, don’t hesitate to get help. Alongside professional medical staff, family, and friends, most are able to get the best of this debilitating condition.

Was this page helpful?
Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Zhou J, Li J, Ma L, Cao S. Zoster sine herpete: a review. Korean J Pain. 2020;33(3):208-215. doi:10.3344/kjp.2020.33.3.208

  2. Cleveland Clinic. Shingles (herpes zoster): symptoms, treatment & prevention. Updated February 17, 2020.

  3. National Center for Immunization and Respiratory Diseases. Herpes zoster diagnosis, testing, lab methods. Updated September 19, 2019.

  4. Ciancia S, Crisafi A, Fontana I, De Fanti A, Amarri S, Iughetti L. Encephalitis due to herpes zoster without rash in an immunocompetent 12-year-old girl: case report and review of the literature. BMC Pediatr. 2020;20(1). doi:10.1186/s12887-020-02244-0

  5. Barshak M. Shingles of the eye can cause lasting vision impairment. Harvard Health. 2021.

  6. National Organization for Rare Disorders. Ramsay Hunt Syndrome. 2011.