Shingles, also known as herpes zoster, is a painful rash that develops on one side of the body, often in a stripe pattern. But what exactly triggers this condition? The root cause of shingles is the varicella-zoster virus (VZV) – the very same virus that causes chickenpox. After you recover from chickenpox, VZV remains dormant in your nerve tissues. Shingles represents a reactivation of this dormant virus.
The varicella-zoster virus belongs to the herpesvirus family and is highly contagious, primarily spread through airborne droplets or direct contact with fluid-filled blisters during the chickenpox phase. Once infected, the body’s immune system typically clears the active chickenpox infection, but the virus doesn’t entirely leave your system. Instead, it retreats to nerve cells near the spinal cord and brain, where it can lie inactive for decades.
The precise reason why VZV reactivates and causes shingles isn’t fully understood. However, it’s strongly linked to a decline in the immune system’s ability to keep the virus suppressed. This weakening of the immune system can be triggered by several factors, most notably:
- Age: The risk of shingles increases significantly as people age, particularly after 50. This is because the immune system naturally weakens with age, making it less effective at keeping the dormant VZV in check.
- Weakened Immune System: Conditions or treatments that compromise the immune system greatly elevate the risk of shingles. This includes:
- Medical conditions: HIV/AIDS, certain cancers like lymphoma and leukemia, and autoimmune diseases can weaken immunity.
- Medications: Immunosuppressant drugs, often used after organ transplants or to treat autoimmune disorders, can increase shingles risk. Corticosteroids can also suppress the immune system with long-term use.
- Stress: Periods of significant physical or emotional stress can temporarily weaken the immune system, potentially triggering VZV reactivation.
- Other illnesses: Infections or other illnesses can put stress on the immune system and may increase the likelihood of shingles.
Once reactivated, the varicella-zoster virus travels along nerve pathways to the skin, leading to the characteristic shingles rash. This rash typically presents as blisters that scab over in 7 to 10 days and fully clears within two to four weeks. Before the rash appears, people often experience pain, itching, or tingling in the area where the rash will develop. One of the most concerning complications of shingles is postherpetic neuralgia (PHN), a condition characterized by persistent nerve pain in the area affected by shingles, even after the rash has healed.
While there’s no cure for shingles, prompt antiviral treatment can help reduce the severity and duration of the illness, as well as lower the risk of PHN. Furthermore, vaccination is a highly effective strategy for preventing shingles and its complications. The Shingrix vaccine, approved for adults 50 and older and for those 19 and older with weakened immune systems, is highly recommended. Shingrix is a nonliving vaccine given in two doses and has proven to be very effective in preventing shingles and postherpetic neuralgia. Even if you’ve had shingles before, vaccination is still recommended to prevent recurrence.
In conclusion, shingles is caused by the reactivation of the varicella-zoster virus, which remains dormant in the body after a chickenpox infection. Factors that weaken the immune system, such as age, certain medical conditions, medications, and stress, can trigger this reactivation. Understanding the causes of shingles highlights the importance of preventive measures, particularly vaccination with Shingrix, to protect against this painful condition and its potential long-term complications. Consult with your healthcare provider to discuss your individual risk factors and the best strategies for shingles prevention.
