Shingles is a severely painful skin rash caused by the varicella zoster virus (VZV), the same virus which causes chickenpox.

Shingles is caused by the varicella zoster virus (VZV), which also causes chickenpox. After people get chickenpox, the VZV can lay dormant in their bodies, staying in certain nerve cells. When the immune system gets weakened, the virus can get reactivated, causing shingles. Factors which can lead to a weaker immune system include old age, cancer, HIV or AIDS, and certain medications that suppress the immune system.

Shingles typically presents as a painful rash which starts as reddish bumps that gradually fill up with fluid after a few days. Symptoms like itching, tingling, or intense pain may be felt even before the rash appears. The rash usually occurs only on one side of the trunk or the face, and clears up after two to four weeks. In some cases, even after the rash is gone, the pain may last for months to years; this complication is called post-herpetic neuralgia. Other symptoms of shingles may include:
• Fever
• Chills
• Headache
• Increased sensitivity to light
• Upset stomach

In most cases, the diagnosis is made based on the presence of the characteristic rash, along with associated symptoms (like itching or pain) which appear before the rash. In certain cases where diagnosis is uncertain, a sample can be taken from the affected skin and then tested for the varicella zoster virus. Shingles is usually treated with antiviral medications, like valacyclovir or famciclovir. Pain medications are also given to adequately control the pain from the rash; options include paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs), or opioids (for more severe pain). It is also important to practice measures to soothe and protect the skin, like:
• keeping the rash clean and dry, by washing affected skin with soap and water and patting dry carefully
• considering soaking the affected area using warm or cool astringents
• applying sterile non-adherent dressing to promote healing
• wearing loose-fitting clothes

The best way to prevent getting shingles is to prevent getting chickenpox in the first place. This can be done by getting a chickenpox vaccine, which is usually given in children or adults who have not had chickenpox before. In healthy adults 50 and older, however, a separate vaccine for shingles is recommended. The shingles vaccine can be given even if the person has already had shingles or is not sure if he/she has had chickenpox before. To prevent spreading the virus to others, an individual with chickenpox or shingles could:
• cover the rash with dressing
• avoid touching the rash
• practice hand hygiene often
• avoid contact with 1) pregnant women who have not had chickenpox or the chickenpox vaccine, 2) premature babies, and 3) people with weakened immune systems (e.g. cancer patients, people living with HIV)