Shingles, also known as herpes zoster, is a painful skin rash caused by the varicella zoster virus, the same virus that causes chickenpox. After a person recovers from chickenpox, the virus lies dormant in the body. Years later, the virus can reactivate as shingles. It’s not fully understood why the virus reactivates in some people and not others, but shingles is more common in older adults and people with weakened immune systems.
What triggers shingles?
While we don’t know the exact cause, certain factors are thought to trigger reactivation of the virus and development of shingles:
- Older age. Shingles is most common in older adults. The risk increases after age 50 and continues to rise with advancing age. Nearly 1 in 3 people will develop shingles during their lifetime.
- Weakened immunity. Anything that weakens the immune system – like HIV/AIDS, cancer, immunosuppressant medications – can trigger shingles. The risk is greatest among people with immune deficiencies.
- Emotional or physical stress. High stress levels may activate shingles. Stressful events like surgery, divorce, or the death of a loved one have been linked to shingles.
- Cancer, chemotherapy or radiation. Cancer itself as well as treatments like chemotherapy and radiation therapy can weaken immunity and reactivate the virus.
- Other infections. Having certain illnesses or infections like tuberculosis, malaria, or herpes simplex can trigger shingles.
In most cases, it’s difficult to identify a specific trigger. Often a combination of the above risk factors is the likely culprit in activating the shingles virus.
Common Triggers
Let’s explore some of the most common potential triggers of shingles in more detail:
Aging
Advanced age is one of the clearest risk factors for shingles. The risk starts rising around age 50 and continues to increase as people get older. According to the CDC:
- People 50-59 years old: Incidence of 10 per 1,000 person-years
- People 60-69 years old: Incidence of 11 per 1,000 person-years
- People 70-79 years old: Incidence of 12 per 1,000 person-years
- People ≥80 years old: Incidence of 13 per 1,000 person-years
Nearly 50% of all shingles cases occur in adults 60 years and older. Experts aren’t sure exactly why age increases the risk, but it may be due to waning immunity as people get older. Cell-mediated immunity declines with age, possibly allowing for viral reactivation.
Weakened Immunity
Anything that weakens or compromises the immune system can activate the dormant varicella zoster virus and trigger shingles. Some key examples include:
- HIV/AIDS – People with HIV are at greater risk for shingles, with about 10 to 20% developing the condition. The risk increases as the disease progresses and immune function declines.
- Cancer – People with certain cancers like leukemia and lymphoma are more prone to shingles, as are individuals undergoing cancer treatments.
- Immunosuppressant medications – Drugs that intentionally suppress the immune system like steroids or medications for autoimmune disorders can contribute to shingles risk.
- Organ transplant – Anti-rejection medications after organ transplants weaken immunity and raise shingles susceptibility.
In essence, any medical condition or treatment leading to immunodeficiency can potentially allow for reactivation of the varicella zoster virus. Keeping the immune system as healthy as possible is key to preventing shingles.
Emotional Stress
High levels of psychological and emotional stress may contribute to shingles risk. Stress activates the body’s fight-or-flight response, causing hormone and immune system changes that could trigger viral reactivation. Examples of stressful life events that have been linked to shingles include:
- Bereavement or loss of a loved one
- Divorce
- Job loss or retirement
- Major family problems
- Moving
- Financial difficulties
Studies show that people who develop shingles report higher average stress levels in the preceding year compared to controls. Things like relaxation techniques, social support, and counseling may help buffer stress and potentially lower shingles risk.
Physical Trauma
Physical injuries, trauma or surgical procedures can activate shingles as well. Any type of trauma or damage to nerve fibers allows transport of the virus from nerve cells to the skin. Examples include:
- Surgery
- Fractures
- Burns
- Major dental work
- Spinal cord injury
Research shows that the risk of shingles is greatest in the 1-2 months following physical trauma. Minimizing injury/trauma when possible, and allowing proper healing time after procedures, may help reduce shingles susceptibility.
Other Infections
Having certain infections appears to trigger shingles in some people by generally weakening immune defenses. Bacterial, fungal and viral infections linked to increased shingles risk include:
- Tuberculosis
- Pneumonia
- Malaria
- Herpes simplex virus
- Hepatitis
It’s thought that fighting these acute infections taxes the immune system and reduces its ability to keep the varicella zoster virus in check. Avoiding infections through vaccination, proper hygiene and prompt treatment may lower shingles risk.
Who’s at Risk?
While any adult who’s had chickenpox can develop shingles, certain groups are at increased risk. In addition to the triggers above, the following characteristics or conditions raise susceptibility:
- Older than 50 years of age
- Female gender
- Caucasian race
- Immunocompromised state
- Family history of shingles
- Existing conditions like diabetes, COPD, asthma
- Psychological stress
- Trauma or surgery
Being aware of personal shingles risk factors allows people to take preventive steps when possible. Keeping up-to-date with adult vaccinations, limiting stress, and maintaining a healthy lifestyle and diet may help reduce odds of viral reactivation.
Can Shingles Be Prevented?
There are several steps that may help prevent shingles, or at least reduce risks:
- Shingles vaccine – Two doses of the recombinant zoster vaccine Shingrix provides >90% protection and is recommended for adults 50+.
- Chickenpox vaccination – Getting children vaccinated helps prevent initial varicella zoster infection and subsequent shingles later in life.
- Stress management – Relaxation, social support, counseling and/or medications can help control high stress.
- Healthy lifestyle – Good sleep, nutrition, exercise and quitting smoking may optimize immune defenses against viral reactivation.
- Prompt treatment of infections – Quickly treating illnesses to avoid prolonged immune activation may help prevent triggers.
While it’s not always possible to prevent shingles altogether, being proactive gives the best chance of avoiding this painful viral infection.
Treatment Options
Several medications are available to treat shingles once it develops:
Antiviral Medications
Antiviral drugs like acyclovir, valacyclovir, or famciclovir can help shorten the duration of shingles. They work by stopping the virus from multiplying and spreading. Antivirals are most effective if started within 1-3 days of the initial shingles rash.
Pain Medications
Over-the-counter pain relievers like acetaminophen, ibuprofen or aspirin may provide mild relief. Prescription opioids or numbing agents are sometimes needed for more severe nerve pain.
Anti-Itch Medications
Topical calamine lotion or antihistamine tablets can help manage itching caused by the shingles rash.
Corticosteroids
Steroid creams and oral medications help tone down the immune response and inflammation involved in shingles.
In addition to medications, wet compresses, gentle skin care, and wearing loose clothing may enhance comfort while shingles heals. Most cases clear within 2-4 weeks.
Complications
While shingles usually resolves on its own, complications can sometimes occur:
- Postherpetic neuralgia – Nerve pain lasting months to years after the rash has healed, most common in older adults
- Bacterial skin infections – Typically caused by scratching shingles blisters
- Eye problems – If shingles affects the face/eye, including blindness, optic neuritis and keratitis
- Neurological issues – Meningitis, encephalitis, or facial paralysis
- Ear problems – Potential hearing loss and tinnitus if shingles impacts the ear
- Pneumonia – Shingles may affect lung function and raise pneumonia risk
Seeking prompt medical treatment at the first sign of complications can often prevent lasting problems. Staying up-to-date on adult vaccinations and maintaining proper immune function are the best ways to avoid shingles altogether.
FAQs
Can stress cause shingles?
Yes, high levels of psychological and emotional stress may potentially trigger shingles by impacting immune defenses. Stress management techniques are important for reducing shingles risk.
Can shingles be triggered twice?
It’s possible but uncommon to get shingles more than once. About 5% of people will have a recurrence. The shingles virus usually provides immunity against further reactivation once infected.
Can shingles trigger from surgery?
Yes, having surgery can activate shingles, likely due to the trauma and stress of the procedure. The risk seems greatest in the 1-2 months following surgery.
Is shingles contagious?
Shingles itself is not contagious. However, the varicella zoster virus that causes shingles can spread from an infected person to cause chickenpox in someone not immune to the virus.
Who is most at risk for shingles?
Older adults, people over 50, and those with weakened immune systems or existing health conditions have the greatest risk of developing shingles.
The Bottom Line
Shingles is a painful rash resulting from reactivation of the chickenpox virus in people who have previously had the infection. What triggers the dormant virus to reawaken in some individuals remains unclear. Older age, weakened immunity, stress, trauma and other infections seem to be contributing factors. While shingles cannot always be prevented, vaccination and healthy lifestyle habits provide the best defense against this common viral illness.