Shingles is caused by the same virus that causes chickenpox. After an attack of chickenpox, the virus remains in the tissues in your nerves. As you get older, or if you have an illness or stress that weakens your immune system, the virus may reappear in the form of shingles.
You may first have a headache, flu-like symptoms (usually without a fever), and sensitivity to light, followed by itching, tingling, or pain in the area where a rash may develop . The pain usually occurs several days or weeks before a rash appears on the left or right side of your body. The rash will be in a band, a strip, or a small area. In 3 to 5 days, the rash turns into fluid-filled blisters that ooze and crust over. The rash heals in about 2 to 4 weeks, although you may have long-lasting scars. A few people won't get a rash, or the rash will be mild.
Most people who get shingles will not get the disease again.
Complications of shingles
Delaying or not getting medical treatment may increase your risk for complications. Complications of shingles include:
- Postherpetic neuralgia (PHN), which is pain that does not go away within 1 month. It may last for months or even years after shingles heals. It is more common in people age 50 and older and in people who have a weakened immune system due to another disease, such as diabetes or HIV infection.
- Disseminated zoster, which is a blistery rash that spreads over a large portion of the body and can affect the heart, lungs, liver, pancreas, joints, and intestinal tract. Infection may spread to nerves that control movement, which may cause temporary weakness.
- Cranial nerve complications. If shingles affects the nerves originating in the brain (cranial nerves), complications may include:
- Inflammation, pain, and loss of feeling in one or both eyes. The infection may threaten your vision. A rash may appear on the side and tip of the nose (Hutchinson's sign).
- Intense ear pain, a rash around the ear, mouth, face, neck, and scalp, and loss of movement in facial nerves (Ramsay Hunt syndrome). Other symptoms may include hearing loss, dizziness, and ringing in the ears. Loss of taste and dry mouth and eyes may also occur.
- Inflammation, and possibly blockage, of blood vessels, which may lead to stroke.
- Scarring and skin discoloration.
- Bacterial infection of the blisters.
- Muscle weakness in the area of the infected skin before, during, or after the episode of shingles.