Shingles, or herpes zoster, is a viral infection caused by the varicella-zoster virus (VZV), the same virus responsible for chickenpox. While commonly known for its painful skin rash, shingles can also affect internal organs and present without a visible rash. This less common manifestation is often called “internal shingles.” Its diagnosis is challenging due to the absence of the typical rash, making awareness of its varied presentations important for understanding its impact on the body.
Understanding Shingles Beyond the Skin
After causing chickenpox, the varicella-zoster virus remains dormant in nerve cells. Years or decades later, this dormant virus can reactivate. Upon reactivation, the virus travels along nerve pathways, sometimes extending beyond those supplying only the skin. “Internal” shingles means the virus affects nerves connected to internal organs or tissues, causing symptoms in those areas, with or without the familiar skin rash. Shingles occurring without the typical rash is known as “zoster sine herpete.”
Manifestations of Internal Shingles
Internal shingles manifests in diverse ways, depending on the affected nerves and organs. When the virus affects the ophthalmic nerve, a branch of the trigeminal nerve, it is called ophthalmic shingles. This can cause eye pain, inflammation, and vision changes, with potential for severe or permanent vision loss, often due to corneal scarring. About 1 in 10 individuals with ophthalmic shingles experience moderate or severe vision loss.
Shingles can also cause neurological manifestations beyond skin nerve pain. Ramsay Hunt Syndrome occurs when the virus affects the facial nerve near the ear, causing facial paralysis and sometimes a painful rash with blisters. This syndrome can also lead to ear pain, hearing loss, ringing in the ears, and vertigo. It can occur without a visible rash. More widespread neurological complications include severe headaches, meningitis (inflammation of brain and spinal cord membranes), encephalitis (brain inflammation), and myelitis (spinal cord inflammation). These conditions can arise if the virus spreads to the brain or spinal cord, potentially causing long-term neurological damage.
Visceral shingles involves the virus affecting internal organs like the lungs (causing pneumonitis), liver (leading to hepatitis), or gastrointestinal tract (resulting in abdominal pain or bowel dysfunction). The bladder can also be impacted, possibly causing urinary retention. These varied symptoms can occur without any rash, making diagnosis especially challenging in cases of zoster sine herpete.
Diagnosis and Management
Diagnosing internal shingles is challenging, especially when the typical rash is absent or symptoms are atypical. Diagnosis relies on a comprehensive assessment, including medical history (like prior chickenpox infection and risk factors) and symptom presentation (especially unexplained nerve pain on one side of the body). Laboratory tests confirm diagnosis, including PCR testing for VZV DNA from affected tissues, cerebrospinal fluid, or blood. Antibody testing can also indicate VZV presence.
Primary treatment for internal shingles involves antiviral medications like acyclovir, valacyclovir, and famciclovir. These medications reduce viral replication and lessen infection severity and duration. Early administration, ideally within three days of symptom onset, helps prevent complications. Pain management is also a significant part of treatment, often involving over-the-counter pain relievers, or stronger medications and nerve blocks for severe pain. Supportive care is tailored to the specific affected organ or system, aiming to manage symptoms and prevent further damage.
Risk Factors and Prevention
Several factors increase susceptibility to shingles. Age is a significant risk factor, with risk increasing considerably in individuals over 50. A weakened immune system is another prominent factor, resulting from conditions like HIV, certain cancers, or chemotherapy. Immune-suppressing medications, such as those for psoriatic arthritis or organ transplant recipients, also elevate risk. Anyone who has previously had chickenpox carries the dormant varicella-zoster virus, making them susceptible to shingles reactivation.
Vaccination is the most effective method for preventing shingles and its complications. The shingles vaccine, Shingrix, is recommended for healthy adults aged 50 and older, and for adults 19 and older with weakened immune systems. Given in two doses, it offers over 90% protection. Even if an individual has had shingles, vaccination is still recommended to reduce future occurrences.