What causes chickenpox?

Both chickenpox and shingles are caused by the varicella-zoster virus. The difference between chickenpox and shingles is that chickenpox usually occurs first, and shingles are a result of a reactivation of chickenpox later on.

Even though chickenpox and shingles are usually spoken of together, they are very different illnesses. Some think only kids get chickenpox, and only older adults get shingles. Neither is entirely true. So, what’s the difference between chickenpox and shingles? Though caused by the same virus, chickenpox usually occurs first, and shingles are a result of a reactivation of chickenpox later on. The difference is not in the age of the patient but in the order in which the virus progresses.

Chickenpox is caused by the virus varicella-zoster. It is very contagious. The virus can be transmitted from person to person by touching the mucus, saliva, or blisters of someone infected. Also, the virus can be transmitted by sneezing or coughing by someone infected. When a person is infected with chickenpox, they can spread the disease in the 1 to 2 days before the associated rash first appears. Contagion usually goes away once the lesions scab over.

There are three phases to chickenpox. Each phase has its associated symptoms and distinct characteristics. Bumps will form during infection with chickenpox. New bumps will continue to form until the virus is gone, so it is possible people can exhibit bumps in all three phases at once. 

What causes shingles?

Just like chickenpox, varicella-zoster is the viral cause of a shingle rash infection. The shingles rash does not appear all over the body like chickenpox. It is usually a single stripe on one side of the torso. It cannot be passed from person to person. Though someone with shingles cannot give another person shingles, during an active infection, they can give chickenpox to people who have never had it before and who are not vaccinated for the virus.

Many people develop shingles later in life after they have had chickenpox. Those who have had chickenpox still have the varicella-zoster virus. The varicella-zoster lies dormant in the nerves near the brain and spinal cord. During a time of lowered immunity, the virus can reactivate and form shingles.

What are the symptoms of chickenpox?

There are very distinct characteristics of those experiencing a chickenpox outbreak:

• The first few symptoms include headache, sudden fever, and fatigue.
• A blistery, itchy rash that usually begins on the face, back, and chest appears 1 to 2 days after.
• The rash continues to infect the rest of the body, with new blisters appearing for an additional 3 to 4 days.
• Usually, the blisters will scab over from drying out and fall off within a week.

What are the symptoms of shingles?

Shingles, or herpes zoster, has its own set of distinct symptoms:

• Itching, tingling, or stabbing pain on the skin.
• A rash appears after seven days as a band of raised dots on the side of the face, trunk, or elsewhere in the body.
• The rash develops into fluid-filled small blisters that dry and crust over in a few days.
• At the peak of the rash, feelings can range from mildly itching to extreme pain.
• Symptoms usually go away before five weeks.

In addition to symptoms related to the rash, those suffering from shingles may also experience: 

What are the risk factors for shingles?

Anyone who has had chickenpox can get shingles. Most adults in the US had chickenpox as children. However, other things can increase your risk of development:

• Having certain diseases: Diseases like HIV/AIDS and cancer weaken your immune system and raise your risk for disease.
• Over 50 years of age: People over 50 are more at risk for shingles because incidence increases with age.
• Cancer treatments: Chemotherapy and radiation lower disease resistance and can cause an outbreak of shingles.
• Taking medications: Drugs like those that resist rejection of transplanted organs can cause an outbreak of shingles. Prolonged use of steroids can also trigger an outbreak.

Common misconceptions about shingles

Shingles and chickenpox are the same diseases: While they are caused by the same virus, they are still separate illnesses. Chickenpox is usually mild and is seen the most in kids. Shingles are a reactivation of this virus in a different form, years after chickenpox has gone away. Shingles usually go away in one month for most but can have long-lasting pain that is hard to treat. 

Shingles are only a rash: While the rash is a specific and well-known symptom, the most associated symptom is pain. This pain can be severe. It may even appear up to four days before the rash and can last longer than the rash. Long-term pain is called post-herpetic neuralgia. It is described as throbbing, burning, stabbing, or shooting pain. Long-term nerve pain, scarring, and muscle weakness can also occur.

Shingles are a rare condition: One million people in the US get shingles annually. Half of the population aged up to 85 will get shingles in their lifetime. As you age, your chance of getting singles increases. People who aren’t vaccinated will likely get shingles as their age increases.

Only older people get shingles: Though we usually see people with shingles as older, it can occur in children or healthy younger adults as well. People with weakened immune systems like those with AIDS and cancer or on certain drug treatments are at a higher risk of getting shingles.

How do you protect yourself?

Both shingles and chickenpox offer vaccination options. For chickenpox, two options are offered:

For shingles, the Centers for Disease Control and Prevention (CDC) advises that healthy adults 50 years of age and older get a shingles vaccine.

Ultimately, good hygiene will help to protect you from contracting chickenpox and shingles:

• Clean your hands often.
• Avoid touching a person infected with shingles or chickenpox.
• Cover the rash.
• Avoid scratching or touching the rash.