Holy Cow, What's Up With This Rash?!

It could be nothing...or it could be serious. Learn how to tell the differences between shingles and other skin conditions.

by Lara DeSanto Health Writer

Picture this: You wake up one morning, roll out of bed, walk into the bathroom, and look in the mirror. Uh oh—something’s up with your skin. There's a strange red rash creeping up your chest, and a tingling feeling along with it. What’s going on? Unexplained skin changes can be disconcerting, not to mention seriously uncomfortable. But should you be worried? Stick with us while we break down the possible causes of your skin situation, from chickenpox to shingles, hives, or even eczema. Then follow these tips to help you get the treatment you need to feel better ASAP.

Is It Chickenpox?

First thing to know: Chickenpox is a skin condition caused by the virus varicella zoster. This virus is a member of the herpes family, says Anna Wald, M.D., head of the allergy and infectious disease division at the University of Washington School of Medicine in Seattle. “There are eight different viruses in the herpes family,” she explains, including the herpes simplex viruses (which cause oral and genital herpes), Epstein-Barr virus (which causes mononucleosis), and more.

Say you don’t remember getting the chickenpox as a kid, and you never got the vaccine—could this virus be the root of your suddenly itchy skin? This may clear things up: Most people (as in more than 99%) born before 1980 in the United States have had chickenpox, according to the Centers for Disease Control and Prevention (CDC)—yes, even if you don’t remember it! And thankfully, it’s super rare to get chickenpox more than once.

But what if you’re younger than 40? Or what if you’re convinced you are part of the 1% of people who never got chickenpox? Let’s take a look at the symptoms of this skin condition.

“Chickenpox gives you a rash all over your body,” rather than hanging out in one isolated area, Dr. Wald says. That rash turns into fluid-filled blisters that are seriously itchy. These eventually scab over and heal after about four to seven days. While an itchy rash is the main sign of chickenpox, other symptoms include fatigue, fever, headache, and loss of appetite.

Even if you have some of these symptoms, it’s worth noting that the illness typically strikes when you’re young, says Edward Jones-Lopez, M.D., infectious disease expert with Keck Medicine at the University of Southern California in Los Angeles. “Typically, this infection occurs in childhood,” he says. “It’s one of those viruses that is transmitted between kids’ saliva and close contact.” That said, technically speaking anyone can get chickenpox. Unfortunately, if you do get it as an adult, it’s usually more severe than a childhood infection.

A final word on the pox: Even if you got the chickenpox vaccine when you were a kid, it’s possible (though not probable) that you can still get the infection. The good news is that cases tend to be much milder (think rash but no blisters).

Could It Be Shingles?

If you’re an older adult and experiencing a blistery rash, the most likely answer is that you’ve got shingles, a.k.a. herpes zoster, which affects one in three people in their lifetime, according to the CDC. Shingles is what’s known as a “reactivation” virus that usually affects older adults, says Dr. Jones Lopez. Basically, once you’ve had chickenpox, the varicella zoster virus stays in your body. “After the initial infection, the virus goes into dormant state for potentially decades,” he says. “Much later in life, when your immunity goes down, it can reactivate as shingles.”

Unlike a chickenpox rash, the shingles rash is usually confined to a specific area of the body and appears in a single band, rather than spreading indiscriminately. “It typically happens somewhere on the chest or back,” says Dr. Jones-Lopez, although the head and other parts of the body can sometimes be affected. “The key thing that distinguishes the shingles rash is that it doesn’t cross the midline. If it spreads across your body, it’s not shingles.” For example, if you’ve got a rash on left side of your face but another on the right side of your back, you can probably rule out this illness.

In addition to a rash (or before a rash even appears), you may have some pain, itching, or tingling on your skin. You may also have flu-like symptoms (fever, chills, upset stomach, and headache). Like chickenpox, shingles rashes may itch—but they are mostly known for causing pain.

Maybe It’s Hives?

Hives, officially called urticaria, are a common cause of skin rashes. Unlike chickenpox and shingles, hives are not caused by a virus. Instead, they are usually the result of an allergic reaction—to insect bites or stings, medicines, food, or other environmental triggers, according to the American College of Allergy, Asthma, and Immunology (ACAAI). Sometimes, the cause is unknown.

While hives and shingles both appear as rashes, the similarities stop there. “Shingles doesn’t look like hives—the onset is very different,” says Dr. Wald. “There’s usually much more pain with shingles.” Meanwhile, if your prominent symptom is itching, it’s more likely to be hives.

The rash appearances are different as well. In lieu of shingles’ blistery surface, hives appear as red, raised bumps called welts or wheals that can vary in size and pop up anywhere on the body; if you press down on the center of one, it will turn white.

Another clue as to whether your rash is hives has to do with duration. Chickenpox lasts about a week; shingles lasts up to a month. Hives, though, are short-term: They typically appear and disappear within a few days (although in rarer cases they can be chronic).

Do I Have Eczema?

Still stumped on the source of your skin outbreak? Another non-viral cause of itchy rashes is called eczema, a.k.a. atopic dermatitis. This condition affects 10% to 20% of kids, but only 1% to 3% of adults, making it less likely to be the culprit, as most people outgrow eczema with age.

Compared with the other rashes, eczema’s appearance tends to be on the dryer, scalier side of things, with plenty of redness and itchiness as well. Eczema can be the result of an allergic reaction to things like dust mites or pet dander, along with other environmental triggers like certain soaps or perfumes.

To distinguish eczema from hives, look for small bumps filled with fluid, says the ACAAI. These bumps can leak liquid that is clear or yellow. Unlike chickenpox, shingles, or hives, eczema is a chronic condition that requires treatment to keep it under control.

The Bottom Line

In addition to chickenpox, shingles, hives, and eczema, there are other possible causes for that itchy skin rash. And while most rashes are mild and don’t cause long-term harm, it’s always a good idea to check with your doctor if there’s something strange going on with your skin. Shingles, for one, responds infinitely better to antiviral treatments if you get them right away, says Dr. Wald. Seek the care of your family doctor or dermatologist if your skin rash persists or comes with other painful or concerning symptoms—they can give you an accurate diagnosis and put you on the road to relief.

Lara DeSanto
Meet Our Writer
Lara DeSanto

Lara is a former digital editor for HealthCentral, covering Sexual Health, Digestive Health, Head and Neck Cancer, and Gynecologic Cancers. She continues to contribute to HealthCentral while she works towards her masters in marriage and family therapy and art therapy. In a past life, she worked as the patient education editor at the American College of OB-GYNs and as a news writer/editor at WTOP.com.