The signs of chickenpox and when you should see a doctor

• The signs of chickenpox include fever, fatigue, headache, loss of appetite, and an itchy rash.
• The rash usually develops about 10 to 21 days after you are exposed to the virus, and the other physical symptoms can occur a few days before the rash develops.
• The infection usually lasts 5 to 10 days and goes away on its own, though certain high-risk groups will want to seek medication.
• This article was reviewed by Jason R. McKnight, MD, MS, a family medicine physician and clinical assistant professor at Texas A&M College of Medicine.

Chickenpox is a very contagious rash that is caused by the varicella-zoster virus (VZV). The chickenpox vaccine was made available in the US in 1995, and today, most people get vaccinated, which has resulted in the prevention of 3.5 million cases of chickenpox. However, it is still possible for people to contract the virus. Here's what you need to know about the symptoms, causes, and treatment of chickenpox.

Signs and symptoms of chickenpox

The itchy rash is the most characteristic feature of chickenpox, and this is what the diagnosis of chickenpox is based on, says Jeremy Fenton, MD, board-certified dermatologist at Schweiger Dermatology Group in New York City.

But about one to two days prior to seeing a rash develop, you may experience symptoms like:

• Fatigue
• Fever
• Headache
• Loss of appetite

A chickenpox rash usually begins to develop about 10 to 21 days after you are first exposed to the virus. The rash will appear in three stages:

1. First, it will start with red spots. Typically, it will first show up on the chest, face, or back before appearing on the skin of other body parts. You can experience these lesions anywhere on the body, ranging from the inside of your mouth to your genitals.
2. Then, those red spots will turn into fluid-filled blisters. "The classic description of the vesicles in chickenpox are 'dewdrops on a rose petal' because of the way that the fluid-filled bumps are sitting on a red rash," Fenton says.
3. Those blisters will eventually scab and crust over.

The infection will usually last five to 10 days, in most cases, and it will typically take about a week for all of the chickenpox blisters to scab over.

Causes of chickenpox

A virus called the varicella-zoster virus (VZV) is responsible for causing chickenpox. If you have never had chickenpox, or you haven't had the chickenpox vaccine, and you're in close proximity to someone who is infected, you're at risk. The virus is highly contagious, and Fenton says you can get it one of two ways:

• By inhaling respiratory droplets from an infected person (if they sneeze or cough, for example)
• By touching the rash of someone with an active chickenpox or shingles outbreak

Treatment of chickenpox

If you or your child does end up having chickenpox, treatment isn't always necessary, especially when a case is mild.

However, the CDC recommends getting medical attention if you are at higher risk of having complications, including those who:

• Are pregnant
• Are immunocompromised
• Are younger than one year old
• Are older than 12 years old, since chickenpox can be more severe in adults

Even if you aren't at risk, but you're experiencing a high fever that lasts more than four days, vomiting, trouble walking, trouble breathing, or rash leaking pus, the CDC also urges you to contact your doctor.

In these cases, antiviral medications that specifically target the varicella-zoster virus may be prescribed. Fenton says some examples of these medications are:

• Acyclovir
• Valacyclovir
• Famciclovir

Aside from antiviral medications, there are also home remedies you can use to ease your discomfort. These include:

• Applying calamine lotion to the rash
• Taking a lukewarm bath with either oatmeal or baking soda, which can reduce itching
• Taking antihistamine medications, such as Benadryl
• Taking acetaminophen (Tylenol) to relieve pain and reduce fever

However, you should not use medications that contain aspirin when you have chickenpox, since it can put you at risk of Reye's syndrome, which causes liver complications.

Prevention of chickenpox

You can prevent getting the virus in the first place with the readily available, safe chickenpox vaccine.

It is still possible to get chickenpox even if you have been vaccinated, however, the case would be much milder and shorter lasting.

Once you've had chickenpox, you're extremely unlikely to get it again. After the primary infection, the varicella-zoster virus will remain dormant in your body. It's possible for the virus to become reactivated later in life, in which case you will develop shingles. Luckily, there is a vaccine specific for shingles, and getting vaccinated can reduce your risk by 90%.

The bottom line

If you suspect you or your child has chickenpox and you're in one of the high-risk groups, do not hesitate to get medical assistance. The sooner you get antiviral medication, the better, and the less likely you are to have complications.

Related articles from Health Reference:

• Here's how you can catch chickenpox from someone with shingles
• If you've had chickenpox you're at risk of a painful condition called shingles — here's why