When the virus that causes chickenpox reactivates, it causes shingles. Early symptoms of shingles include headache, sensitivity to light, and flu-like symptoms without a fever. You may then feel itching, tingling, or pain where a band, strip, or small area of rash may appear several days or weeks later. A rash can appear anywhere on the body but will be on only one side of the body, the left or right. The rash will first form blisters, then scab over, and finally clear up over a few weeks. This band of pain and rash is the clearest sign of shingles.
The rash caused by shingles is more painful than itchy. The nerve roots that supply sensation to your skin run in pathways on each side of your body. When the virus becomes reactivated, it travels up the nerve roots to the area of skin supplied by those specific nerve roots. This is why the rash can wrap around either the left or right side of your body, usually from the middle of your back toward your chest. It can also appear on your face around one eye. It is possible to have more than one area of rash on your body.
Shingles develops in stages:
Prodromal stage (before the rash appears)
- Pain, burning, tickling, tingling, and/or numbness occurs in the area around the affected nerves several days or weeks before a rash appears. The discomfort usually occurs on the chest or back, but it may occur on the belly, head, face, neck, or one arm or leg.
- Flu-like symptoms (usually without a fever), such as chills, stomachache, or diarrhea, may develop just before or along with the start of the rash.
- Swelling and tenderness of the lymph nodes may occur.
Active stage (rash and blisters appear)
- A band, strip, or small area of rash appears. It can appear anywhere on the body but will be on only one side of the body, the left or right. Blisters will form. Fluid inside the blisters is clear at first but may become cloudy after 3 to 4 days. A few people won't get a rash, or the rash will be mild.
- A rash may occur on the forehead, cheek, nose, and around one eye (herpes zoster ophthalmicus), which may threaten your sight unless you get prompt treatment.
- Pain, described as "piercing needles in the skin," may occur along with the skin rash.
- Blisters may break open, ooze, and crust over in about 5 days. The rash heals in about 2 to 4 weeks, although some scars may remain.
Postherpetic neuralgia (chronic pain stage)
Postherpetic neuralgia (PHN) is the most common complication of shingles. It lasts for at least 30 days and may continue for months or years. Symptoms are:
- Aching, burning, stabbing pain in the area of the earlier shingles rash.
- Persistent pain that may linger for years.
- Extreme sensitivity to touch.
- The pain associated with PHN most commonly affects the forehead or chest. This pain may make it difficult for the person to eat, sleep, and do daily activities. It may also lead to depression.
Shingles may be confused with other conditions that cause similar symptoms. The rash from shingles may be mistaken for an infection from herpes simplex virus (HSV), poison oak or ivy, impetigo, or scabies. The pain from PHN may feel like appendicitis, a heart attack, ulcers, or migraine headaches.