Shingles (Herpes Zoster): Symptoms, Causes & Treatment

What Is Shingles and What Causes It?

Shingles (herpes zoster) is a viral infection caused by the reactivation of the varicella-zoster virus, the same virus that causes chickenpox. After you recover from chickenpox, the virus remains dormant in nerve tissue near your spinal cord and brain. Years or decades later, it can reactivate and travel along nerve fibers to the skin, causing the characteristic painful rash.

Shingles manifests as a painful rash with fluid-filled blisters that typically appears on one side of the body. The name "shingles" comes from the Latin word "cingulum," meaning belt or girdle, which describes the band-like pattern the rash often takes around the torso. The condition affects an estimated 1 million people in the United States each year, and approximately one in three people will develop shingles at some point in their lifetime.

The varicella-zoster virus belongs to the herpesvirus family, which explains the alternative name "herpes zoster." However, it is important to understand that this virus is completely different from the herpes simplex viruses that cause oral and genital herpes. Once you have had chickenpox, the varicella-zoster virus never leaves your body. Instead, it retreats to clusters of nerve cells called dorsal root ganglia, where it can remain inactive for decades.

The exact mechanism that triggers virus reactivation is not fully understood by scientists. However, research suggests that the immune system plays a crucial role in keeping the virus dormant. When the immune system weakens due to aging, stress, illness, or immunosuppressive medications, the virus may take advantage of this opportunity to reactivate and cause shingles.

Why Do Some People Get Shingles?

Not everyone who has had chickenpox will develop shingles. The vast majority of people who get shingles are otherwise healthy. However, certain factors significantly increase the risk of the virus reactivating. Age is the most important risk factor, with the risk increasing substantially after age 50. This is primarily because the immune system naturally weakens with age, providing less effective surveillance against the dormant virus.

Conditions and treatments that weaken the immune system also increase shingles risk. These include HIV/AIDS, cancer treatments such as chemotherapy and radiation, organ transplant recipients taking immunosuppressive drugs, and long-term use of corticosteroids. Even temporary immune suppression from severe stress or illness can trigger reactivation.

Is Shingles Contagious?

Shingles itself cannot be transmitted from one person to another. However, the varicella-zoster virus can spread from someone with active shingles to a person who has never had chickenpox or received the chickenpox vaccine. In this case, the newly infected person would develop chickenpox, not shingles. The virus spreads through direct contact with fluid from the shingles blisters, not through coughing or sneezing.

Once all the blisters have crusted over and formed scabs, the person is no longer contagious. During the active blister phase, people with shingles should avoid contact with pregnant women who have never had chickenpox, premature or low birth weight infants, and people with weakened immune systems. Neither shingles nor chickenpox can directly cause shingles in another person.

What Are the Symptoms of Shingles?

Shingles symptoms typically develop in stages. Initial symptoms include burning pain, tingling, or sensitivity in a specific area of skin, usually on one side of the body. Within 1-5 days, a red rash appears that develops into fluid-filled blisters. Additional symptoms may include fever, headache, fatigue, and sensitivity to light.

The symptoms of shingles evolve through distinct phases, making early recognition important for timely treatment. Understanding the progression of symptoms can help people seek medical care during the optimal treatment window. The experience of shingles varies considerably between individuals, with some having mild symptoms while others experience severe pain and extensive rash.

Early Warning Signs (Prodromal Phase)

Before the visible rash appears, most people experience what doctors call the prodromal phase. This typically begins 1 to 5 days before the rash and includes sensations in a specific area of skin that signal the virus is traveling along the nerve fiber. These early warning signs include:

• Burning or stinging pain in a localized area, often described as sharp or stabbing
• Tingling or prickling sensations similar to pins and needles
• Unusual sensitivity where even light touch or clothing causes discomfort
• Numbness or a strange sensation in the affected area

Some people also experience general symptoms during this phase, including mild fever, headache, general malaise, and fatigue. These flu-like symptoms can make the early stages of shingles difficult to distinguish from other conditions, which is why the appearance of the characteristic rash is usually what leads to diagnosis.

The Shingles Rash

The hallmark of shingles is a distinctive rash that follows a specific pattern. After the initial prodromal symptoms, the skin in the affected area typically changes in appearance. On lighter skin, it becomes red and inflamed. On darker skin tones, the rash may appear darker than the surrounding skin or may be more difficult to detect visually.

Within a few days, the rash transforms into clusters of fluid-filled blisters. These blisters are initially clear but become cloudy or darker over time. The blisters are often intensely itchy and can be quite painful. The rash typically follows a band-like pattern on one side of the body, corresponding to the nerve (dermatome) that the virus travels along. Common locations include the torso (wrapping around like a belt), the face, and occasionally the arms or legs.

Shingles Near the Eye (Herpes Zoster Ophthalmicus)

When shingles affects the ophthalmic branch of the trigeminal nerve, it can involve the eye and the skin around it. This condition, called herpes zoster ophthalmicus, occurs in about 10-20% of shingles cases and requires urgent medical attention. Symptoms may include redness and swelling of the eyelid, eye pain that can be severe, sensitivity to light (photophobia), blurred or double vision, and feeling that something is in the eye.

Without prompt treatment, shingles affecting the eye can lead to serious complications including corneal scarring, chronic eye inflammation, and even permanent vision loss. If you develop shingles symptoms on your forehead, around your eye, or on the tip of your nose (known as Hutchinson's sign), seek immediate medical care.

When Should You See a Doctor for Shingles?

Seek medical care as soon as you suspect shingles, ideally within 72 hours of rash onset. This is when antiviral treatment is most effective. Seek immediate emergency care if shingles affects your eye area, you have a weakened immune system, the rash is widespread, or you experience severe pain or high fever.

Timing is critical when it comes to shingles treatment. Antiviral medications, which are the mainstay of shingles treatment, work best when started within 72 hours of the rash appearing. This early intervention can reduce the severity and duration of the illness and may help prevent complications such as postherpetic neuralgia.

Mild Cases in People Under 50

If you are under 50 years old and have mild symptoms, shingles often resolves on its own without specific treatment. However, it is still advisable to contact a healthcare provider to confirm the diagnosis and discuss whether antiviral treatment might benefit you. Over-the-counter pain relievers and home care measures can help manage symptoms during the healing process.

When Prompt Medical Care Is Essential

Certain situations require prompt medical evaluation. Contact a healthcare provider as soon as possible if any of the following apply to you:

• You are 50 years or older – antiviral treatment is recommended to reduce complication risk
• You have a weakened immune system due to disease or medication
• You experience severe pain that interferes with daily activities or sleep
• The rash or pain involves your face, especially near the eye
• You feel very ill with high fever or widespread symptoms
• The rash is spreading extensively or crossing the midline of your body

How Is Shingles Diagnosed?

Shingles is usually diagnosed through visual examination of the characteristic rash. The distinctive band-like pattern of painful blisters on one side of the body is typically sufficient for diagnosis. Laboratory tests such as PCR or viral culture may be used if the diagnosis is uncertain or if the rash is atypical.

For most patients, a healthcare provider can diagnose shingles simply by examining the rash and asking about symptoms. The combination of a painful, blistering rash that follows a dermatomal pattern (confined to one side of the body along a nerve pathway) is highly characteristic. The doctor will also ask about your medical history, including whether you have had chickenpox and whether you have any conditions that might weaken your immune system.

In some cases, particularly when the presentation is unusual or when the diagnosis needs to be confirmed, laboratory testing may be performed. The most accurate test is polymerase chain reaction (PCR), which detects the viral DNA from a swab of the blister fluid or a tissue sample. Viral culture is another option, though it takes longer and is less sensitive than PCR. Blood tests for antibodies are generally not helpful for diagnosing active shingles.

If shingles affects the face, an eye examination by an ophthalmologist may be necessary to check for eye involvement. Early detection and treatment of herpes zoster ophthalmicus is essential to prevent potential vision complications.

How Is Shingles Treated?

Shingles treatment focuses on antiviral medications to reduce virus activity and pain management. Antiviral drugs like acyclovir, valacyclovir, or famciclovir are most effective when started within 72 hours of rash onset. Pain is managed with over-the-counter or prescription medications, and the rash is treated with good skin care to prevent infection.

The goals of shingles treatment are to shorten the duration of the illness, reduce the severity of symptoms, prevent complications (especially postherpetic neuralgia), and manage pain effectively. Treatment approaches may vary depending on the patient's age, overall health, and the severity of their symptoms.

Antiviral Medications

Antiviral drugs are the cornerstone of shingles treatment for many patients. These medications do not kill the virus but inhibit its ability to replicate, which helps the immune system bring the infection under control more quickly. The three main antiviral medications used for shingles are:

• Acyclovir (Zovirax) – the oldest option, requires more frequent dosing (five times daily)
• Valacyclovir (Valtrex) – better absorbed, taken three times daily
• Famciclovir (Famvir) – similar effectiveness to valacyclovir, taken three times daily

These medications are typically prescribed for 7 days and are most effective when started within 72 hours of the rash appearing. Even if more than 72 hours have passed, antiviral treatment may still be beneficial for certain patients, including those with severe symptoms, immunocompromised individuals, and those with eye involvement.

Patients with weakened immune systems or severe disease may require intravenous antiviral therapy and possibly hospitalization. The eye involvement in herpes zoster ophthalmicus also requires aggressive treatment to prevent vision-threatening complications.

Pain Management

Pain is often the most distressing aspect of shingles and may persist even after the rash has healed. A stepped approach to pain management typically includes:

Over-the-counter pain relievers: Acetaminophen (paracetamol) and nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen can help with mild to moderate pain. These are often sufficient for younger patients with uncomplicated shingles.

Prescription pain medications: For more severe pain, doctors may prescribe stronger medications including opioid pain relievers for short-term use, tricyclic antidepressants (which have pain-relieving properties independent of their antidepressant effects), anticonvulsants such as gabapentin or pregabalin, and topical treatments including lidocaine patches or capsaicin cream.

Caring for the Rash at Home

Proper care of the shingles rash can help prevent secondary bacterial infection and promote healing. Basic rash care includes washing the affected area gently with mild soap and water at least once daily, keeping the rash covered with a clean, non-adhesive bandage, avoiding scratching or picking at the blisters, and wearing loose, comfortable clothing to avoid irritation.

To relieve itching and discomfort, you can apply cool, wet compresses to the affected area, use calamine lotion or similar soothing lotions, try colloidal oatmeal baths, and ask your pharmacist about over-the-counter anti-itch medications. Avoid using creams or ointments containing hydrocortisone, as these may increase the risk of bacterial infection in the blisters.

What Are the Complications of Shingles?

The most common complication of shingles is postherpetic neuralgia (PHN), a condition where nerve pain persists for months or years after the rash heals. About 10-18% of people with shingles develop PHN, with risk increasing significantly with age. Other complications include eye problems, bacterial skin infections, and rarely, neurological complications.

While most cases of shingles heal without lasting problems, some people experience complications that can significantly impact their quality of life. Understanding these potential complications can help you recognize warning signs and seek appropriate care.

Postherpetic Neuralgia (PHN)

Postherpetic neuralgia is the most common complication of shingles, affecting approximately 10-18% of people who develop the condition. PHN is defined as pain that persists for more than 90 days after the onset of the shingles rash. The pain can be constant or intermittent, and is often described as burning, stabbing, or aching. Some people also experience extreme sensitivity to touch (allodynia), where even light contact with clothing or a breeze can cause pain.

The risk of developing PHN increases substantially with age. While less than 5% of people under 50 develop PHN, the rate rises to about 20% in those over 70 and can exceed 30% in those over 80. Other risk factors include severe pain during the acute shingles episode, a more extensive rash, and delayed antiviral treatment.

PHN can be challenging to treat and may require a combination of therapies. Options include topical lidocaine patches, capsaicin cream, oral medications such as gabapentin, pregabalin, or tricyclic antidepressants, and in some cases, nerve blocks or other interventional procedures. Some people with PHN experience gradual improvement over time, while others may have symptoms for years.

Eye Complications

When shingles affects the ophthalmic nerve, it can lead to serious eye problems. Potential complications include corneal damage and scarring, inflammation inside the eye (uveitis), glaucoma (increased eye pressure), and vision loss, which may be permanent in severe cases. Prompt treatment with antivirals and ophthalmology care can significantly reduce the risk of these complications.

Other Possible Complications

Additional complications that can occur with shingles include bacterial skin infections if blisters become contaminated with bacteria, scarring or skin color changes at the site of the rash, hearing loss, facial paralysis, or balance problems if shingles affects the ear (Ramsay Hunt syndrome), and in rare cases, encephalitis (brain inflammation) or stroke.

How Can You Prevent Shingles with Vaccination?

The shingles vaccine (Shingrix) is highly effective, providing more than 90% protection against shingles and postherpetic neuralgia. It is recommended for adults 50 years and older and for adults 19 and older with weakened immune systems. The vaccine is given in two doses, 2-6 months apart.

Vaccination is the most effective way to prevent shingles and its complications. Two vaccines have been developed for shingles prevention, though one (Zostavax) is no longer available in many countries because the newer vaccine (Shingrix) is significantly more effective.

Shingrix (Recombinant Zoster Vaccine)

Shingrix is the preferred shingles vaccine and represents a major advance in shingles prevention. It contains a piece of the virus (a protein called glycoprotein E) along with an adjuvant that boosts the immune response. This combination produces strong, long-lasting immunity without using a live virus.

Clinical trials have shown that Shingrix provides more than 97% protection against shingles in adults 50-69 years old, more than 91% protection in adults 70 years and older, and similar high levels of protection against postherpetic neuralgia. Protection remains above 85% for at least four years after vaccination, with studies ongoing to determine how long immunity lasts.

Shingrix is given as a two-dose series, with the second dose administered 2-6 months after the first. Both doses are necessary for full protection. Common side effects include pain, redness, or swelling at the injection site, muscle pain, fatigue, headache, and fever. These side effects are generally mild to moderate and typically resolve within 2-3 days.

Who Should Get the Shingles Vaccine?

The shingles vaccine is recommended for:

• Adults 50 years and older – even those who have already had shingles, as it can recur
• Adults 19 years and older with weakened immune systems – due to disease or immunosuppressive therapy
• People who received the older Zostavax vaccine – Shingrix provides better protection
• People who are unsure if they had chickenpox – most adults born before 1980 have been exposed

The vaccine is typically not covered by public health programs in many countries, meaning you may need to pay for it yourself. However, given the potential severity of shingles and PHN, many healthcare providers strongly recommend vaccination for eligible individuals.

How Long Does Shingles Last and What Is the Recovery Like?

Shingles typically heals within 2-4 weeks. The blisters usually dry and crust over within 7-10 days, with scabs falling off within a few weeks. Most people can continue normal activities during the illness, though severe cases may require time off work. The main concern is lingering pain, which is more likely in older adults.

Understanding the typical course of shingles can help you know what to expect during recovery. While the experience varies from person to person, most cases follow a predictable pattern of rash development, crusting, and healing.

The active blistering phase typically lasts 7-10 days, after which the blisters dry out and form crusts (scabs). These scabs usually fall off within 2-4 weeks, and the underlying skin may have some temporary changes in color or texture. Scarring can occur, particularly if the blisters become infected with bacteria or if you scratch them excessively.

Pain is often the most persistent symptom. While the rash heals relatively quickly, pain may continue for weeks or even months after the skin has recovered. For most people under 50, the pain resolves within a few weeks. However, older adults have a higher risk of prolonged pain (postherpetic neuralgia), which can last for months or years.

Can You Get Shingles More Than Once?

Yes, it is possible to have shingles more than once, although most people only experience it once. Studies suggest that about 1-6% of people who have had shingles will have a recurrence, with rates being higher in people with weakened immune systems. This is one reason why vaccination is recommended even for people who have already had shingles.

Shingles During Pregnancy

Shingles during pregnancy is uncommon. If you have had chickenpox before pregnancy, your baby is protected by your antibodies even if you develop shingles. Pregnant women who have never had chickenpox should avoid contact with people who have active shingles to prevent getting chickenpox, which can affect the developing baby.

Developing shingles while pregnant is relatively rare, especially in younger women. If you do develop shingles during pregnancy and you have previously had chickenpox, the good news is that your baby is protected. Your immune system has already developed antibodies against the varicella-zoster virus, and these antibodies cross the placenta to provide protection to your baby. This protection continues for several months after birth.

The main concern is for pregnant women who have never had chickenpox and are exposed to someone with active shingles. While shingles is much less contagious than chickenpox, there is a small risk of transmission through direct contact with blister fluid. If a pregnant woman who has never had chickenpox contracts the virus, she would develop chickenpox, not shingles. Chickenpox during pregnancy carries risks for the developing baby, including a small chance of birth defects or, if infection occurs near delivery, severe neonatal chickenpox.

If you are pregnant and have never had chickenpox, avoid close contact with anyone who has active shingles, especially contact with their blisters. If you think you have been exposed, contact your healthcare provider immediately.