Many adults remember the itchy, spotty rash of chickenpox as a nearly universal rite of passage from their childhood. After the illness resolves, most people assume the virus is gone forever. But in reality, the virus never leaves. It retreats into the body’s nerve cells, where it lies dormant for decades, waiting for a chance to reawaken. When it does, it emerges not as chickenpox, but as a different and far more painful condition: shingles, known medically as herpes zoster. Shingles cause a distinctive, blistering rash on one side of the body, often accompanied by intense nerve pain. While not usually life-threatening, it can be an excruciatingly painful illness with the potential for serious, long-term complications. Understanding shingles, its connection to chickenpox, and the importance of prompt treatment and prevention are key to managing this common viral infection.

Shingles is a viral infection that causes a painful skin rash. It is a reactivation of the varicella-zoster virus (VZV), the exact same virus that causes chickenpox. You cannot get shingles unless you have previously had chickenpox or, in very rare cases, the chickenpox vaccine.

The life cycle of the varicella-zoster virus is a two-act play:

• Act I: Chickenpox (Varicella). The first time a person is exposed to VZV, it causes the primary infection, chickenpox, which is characterized by a widespread, itchy, blistering rash.
• Act II: Shingles (Herpes Zoster). After the chickenpox infection clears, the virus is not eliminated from the body. Instead, it travels up the sensory nerves and settles into a dormant, or latent, state in the dorsal root ganglia, nerve cell clusters located alongside the spinal cord. It can remain there silently for decades.

Shingles occurs when, years later, this dormant virus reactivates. When it “wakes up,” it does not cause another case of chickenpox. Instead, it travels back down the pathway of a single sensory nerve to the area of skin supplied by that nerve. This is why the shingles rash appears in a stripe-like pattern, called a dermatome, on only one side of the body, never crossing the midline.

I often tell patients that shingles is like your immune system “forgetting” the virus is there, then it reawakens, following a nerve, and causes significant discomfort. It’s more than just a rash, it’s a nerve condition with skin symptoms.

Shingles is caused by reactivation of latent varicella-zoster virus (VZV). The underlying reason for this reactivation is a decline in a person’s cell-mediated immunity specifically to VZV.

Throughout your life after having chickenpox, your immune system acts as a vigilant guard, constantly suppressing the dormant virus and keeping it locked away in the nerve cells. As long as your immune system is strong and vigilant, the virus remains inactive. However, if your immune system’s specific ability to control VZV weakens, the virus can seize the opportunity to multiply and travel back down the nerve to the skin, causing the inflammation and rash of shingles.

When patients ask if they “caught” shingles, I clarify that it came from within. They already had the virus sleeping in their system, just waiting for the right conditions to resurface.

You can’t catch shingles from someone else, but if you’ve had chickenpox, the virus is already in your body and may reactivate later in life. However, there are some important points about transmission:

• A person with an active shingles rash can transmit the varicella-zoster virus to someone who has never had chickenpox or the chickenpox vaccine. In this case, the newly infected person would develop chickenpox, not shingles.
• The virus is spread through direct contact with fluid from shingles blisters. It is not spread through the air.
• A person with shingles is only contagious once the blisters appear and until they have completely crusted over.

The risk factors for developing shingles are all factors that can lead to a weakening of the immune system.

• Having had chickenpox: This is the essential prerequisite. Approximately 99% of adults born before 1980 have had chickenpox, even if they do not remember it (CDC, 2023).
• Age: This is the most significant risk factor. The risk of getting shingles increases dramatically with age, particularly after the age of 50. This is due to a natural, age-related decline in immune function known as immunosenescence.
• A Weakened Immune System (Immunosuppression): Any condition or medication that weakens the immune system can allow the VZV to reactivate. This includes:
  • Cancers, especially leukemia and lymphoma.
  • HIV infection.
  • Treatment with immunosuppressive drugs, such as high-dose steroids for other autoimmune diseases, chemotherapy for cancer, or medications taken after an organ transplant.
• Physical or Emotional Stress: While less well-defined, periods of intense stress are also thought to potentially contribute to a temporary weakening of the immune response, allowing for reactivation.

I’ve seen shingles triggered not just by illness but by emotional stress or burnout, anything that taxes the immune system can give the dormant virus a chance to wake up.

Shingles symptoms typically appear in stages and follow the path of a single nerve (dermatome).

The Prodromal Phase (Before the Rash)

In the one to five days before any rash appears, a person may experience localized symptoms along the path of the affected nerve. This can include:

• Pain, which can be burning, throbbing, stabbing, or aching.
• Tingling or numbness.
• Itching.
• Extreme sensitivity to touch in that area.
• During this phase, some people may also experience general symptoms like fever, headache, and fatigue.

The Acute Eruptive Phase (The Rash)

A few days after the initial pain begins, the characteristic shingles rash appears in the same location.

• The rash starts as a cluster of red bumps.
• These bumps quickly develop into fluid-filled blisters (vesicles), similar in appearance to chickenpox blisters.
• The rash follows a distinct unilateral, dermatomal pattern.
• New blisters form three to five days.
• The blisters then break, ooze, and form crusts or scabs.
• The scabs typically fall off, and the skin heals over a period of two to four weeks.

The pain during the acute phase can be mild for some but is often moderate to severe for many, especially older adults.

I’ve seen patients who thought they pulled a muscle or had a skin allergy, until the rash appeared. The pattern and location of the pain often give away the diagnosis before the blisters even form.

When to See a Doctor  

It is imperative to see a healthcare provider as soon as possible after the shingles rash appears, ideally within the first 72 hours (3 days). Starting treatment early is the key to a better outcome.

You should seek immediate medical care if:

• The rash and pain are near your eye. Shingles involving the eye, known as herpes zoster ophthalmicus, can lead to permanent vision loss if not treated urgently by an ophthalmologist.
• You are over 60.
• You or someone in your household has a weakened immune system.
• The rash is widespread and very painful.

Diagnosis

Shingles is usually diagnosed clinically based on the rash pattern, pain, and history of chickenpox. The characteristic story of localized pain followed by the appearance of a unilateral, blistering rash in a dermatomal pattern is usually unmistakable.

If the diagnosis is uncertain (for example, if the rash is atypical or if there are no blisters), a doctor can take a swab of fluid from a blister and send it to a laboratory for a viral culture or a polymerase chain reaction (PCR) test to confirm the presence of the varicella-zoster virus.

Shingles has a distinct presentation. When I see a painful, one-sided rash that follows a nerve path, especially in someone over 50, I can almost always confirm it clinically.

Treatment

There is no cure for shingles, but treatment can help speed recovery and reduce the risk of serious complications.

• Antiviral Medications: This is the cornerstone of treatment. Prescription antiviral drugs, such as acyclovir, valacyclovir, and famciclovir, work by stopping the VZV from multiplying. To be most effective, these medications must be started within 72 hours of the rash first appearing.
• Pain Management: Controlling the often-severe pain is a major part of treatment. This can include:
  • Over-the-counter painkillers like acetaminophen or ibuprofen.
  • Cool compresses applied to the rash.
  • Soothing lotions like calamine lotion.
  • For severe pain, a doctor may prescribe stronger pain medications, including certain antidepressants or anti-seizure drugs that work on nerve pain, or in some cases, opioids.

When patients start antivirals early, the difference in recovery is striking. I always urge prompt treatment, not just to help with the rash, but to reduce the risk of long-term nerve pain.

Complications

• Postherpetic Neuralgia (PHN): This is the most common and feared complication of shingles, affecting 10-18% of people who get the disease (NINDS, 2023). PHN is chronic nerve pain that persists in the area of the rash for months or even years after the blisters have healed. It occurs because the virus has caused permanent damage to the nerve fibers. The pain can be debilitating and significantly impact quality of life. The risk of developing PHN increases dramatically with age.
• Herpes Zoster Ophthalmicus: Shingles affecting the eye can cause painful eye infections, glaucoma, and permanent vision loss.
• Ramsay Hunt Syndrome: This occurs when shingles affect the facial nerve near the ear, causing facial paralysis, hearing loss, and vertigo.
• Bacterial Skin Infections: The open blisters can become infected with bacteria, requiring additional treatment with antibiotics.

Prevention: The Power of Vaccination

The most effective way to prevent shingles and its complications is through vaccination.

• Shingrix (Recombinant Zoster Vaccine): This is the modern, highly effective shingles vaccine. It is a non-live vaccine given in two doses, separated by 2 to 6 months.
• Efficacy: The CDC recommends Shingrix for adults 50 years and older, and for adults 19 years and older who have a weakened immune system. It has been shown to be over 90% effective at preventing shingles and postherpetic neuralgia.
• Availability: In many countries, this vaccine is a standard part of preventive healthcare for older adults. However, access and affordability can be a significant consideration depending on the region and local healthcare system. It is important to discuss your personal risk for shingles and vaccine availability with your doctor.

Shingles is a painful and common condition caused by the reactivation of the chickenpox virus that lies dormant in our nerves. Its primary risk factors are age and a weakened immune system, and its most common complication is chronic nerve pain (PHN). The key to a better outcome is twofold. First, for those with symptoms, seeking immediate medical care within the first three days to start antiviral medication is crucial. Second, and most importantly, is prevention. For older adults, prevention through vaccination is the most powerful tool available to avoid the ordeal of shingles and its lasting consequences.

1. Centers for Disease Control and Prevention (CDC). (2023). Shingles (Herpes Zoster). Retrieved from https://www.cdc.gov/shingles/index.html
2. National Institute of Neurological Disorders and Stroke (NINDS). (2023). Shingles: Hope Through Research. Retrieved from https://www.ninds.nih.gov/health-information/public-education/hope-through-research/shingles-hope-through-research
3. American Academy of Dermatology (AAD). (n.d.). Shingles: Overview. Retrieved from https://www.aad.org/public/diseases/a-z/shingles-overview