Any rash caused by a viral infection is known as a viral rash. But how can you tell the difference between a viral rash and other types of rashes (including food allergy hives)? And how do you treat a viral rash? Here’s everything parents need to know about viral rashes.
What is a viral rash? What causes it?
“Viral rash” refers to multiple types of rashes that are all caused by infections with a virus. They usually show up after (or alongside) other symptoms of a viral infection, like fever, congestion, a runny nose, or a cough.
Viral rashes look spotty. These “spots” are often red or pink on babies with lighter skin, and dark red, purple, or brown on babies with darker skin. They tend to spread across larger areas of the body, including the chest or back, and cover both the left and right sides of the body. Some types of viral rashes itch, but many types do not.
Viral rashes usually start to improve, or clear up, within a few days.
Are viral rashes contagious?
The diseases that cause viral rashes are very contagious, especially among babies and young children. They spread through mucus and saliva.
Depending on the virus, your baby could be contagious before a rash develops (while they experience other viral symptoms), and/or for the duration of the rash. Fortunately, the most common rash-causing viral infections tend to be mild.
Different types of viral infections cause different types of symptom patterns, including different types of viral rashes.
Symptoms Of Viral Rashes
There are several different types of viral rashes. Some types of viral rashes are common in babies, while other types are much rarer thanks to widespread vaccinations that fight against them. Here are some well-known types of viral rashes and their symptom patterns.
Roseola, sometimes known as sixth disease, is a common virus that largely affects children under 2. It is caused by herpesvirus 6. The most common symptoms of roseola include an abrupt, high fever (sometimes of up to 105 degrees Fahrenheit) that lasts for 3-5 days, as well as congestion and a cough.
After the fever goes away (or sometimes while the fever is present), roseola causes a viral rash to develop. The rash starts out as small dots on the stomach, then spreads to other parts of the body, such as the neck, back and torso.
This rash is rose-colored on babies with lighter skin. It may be dark red, purple, or skin-colored on babies with darker skin. It is usually raised, but sometimes may be flat. It is not itchy.
Keep in mind that around 15% of babies with roseola experience seizures brought on by the high fever. These seizures are not usually dangerous, but can sometimes cause a loss of consciousness.
Hand, Foot, and Mouth Disease
Hand, foot, and mouth disease is usually caused by a virus called coxsackievirus. It is mild, but common and very contagious. Most commonly, it affects babies and children under the age of 5.
As the name hints at, hand, foot, and mouth disease most commonly causes sores in the mouth, and a viral rash that clusters on the palms of the hands and the soles of the feet. But sometimes, the viral rash may also appear on the elbows, knees, and/or buttocks.
The rash doesn’t itch, but it often looks blistery. It appears dark red on babies with lighter skin, and skin-colored, white, or reddish-purple on babies with darker skin.
For Hand, Foot, and Mouth on darker skin, see here.
Usually, the rashes and sores of hand, foot, and mouth disease appear a few days after the onset of a fever. The sores will appear one to two days after the fever starts, with the rash developing after that. Hand, foot and mouth disease may also cause a sore throat and a loss of appetite.
Fifth disease (erythema infectiosum) is a mild infection caused by a type of parvovirus, and is most common in preschoolers and school-age children. It causes a low fever, a headache, a runny or congested nose, and sometimes vomiting and diarrhea.
After these symptoms resolve, fifth disease causes a viral rash. The first stage of the rash causes the cheeks to appear flushed, as if they were slapped. The second stage of the rash looks lacey, flat, and purplish-red (sometimes reddish-brown). It may spread to the trunk, arms, and legs during this stage. It is sometimes itchy.
Other types of viral rashes
Measles, chicken pox and rubella are also types of viral infections that cause viral rashes. But these rashes are much less common in babies today because of widespread vaccinations. (In the case of rubella, only about 10 people develop it in the U.S. per year, and have only developed it after they’ve traveled to other countries where rubella vaccines aren’t widespread.)
Here are the symptoms of these rarer types of viral rashes:
- Measles causes a flat, spotty rash along the hairline, and then a raised, bumpy rash that spreads to other parts of the body.
- Chicken pox causes a blistery, itchy rash that starts on the head and torso, then spreads.
- Rubella causes a dotted rash on the face, then larger, merged dotted rashes on other areas of the body that usually itch.
All three types of rashes appear after someone develops a fever and other symptoms of a viral infection. But again, these rashes are rare.
Tips For Relieving Baby’s Viral Rash
Viral rashes will eventually go away on their own as baby’s body fights through the viral infection. You won’t be able to treat them with antibiotics because antibiotics don’t work on viruses. So, your best course of action is to help make things more bearable for baby.
- If your baby is over 12 weeks of age and your pediatrician approves a dose, you can give your baby acetaminophen (Tylenol) to help alleviate symptoms.
- Talk to your pediatrician about whether they recommend calamine lotion, or another topical treatment, as a way to soothe the rash.
- Bathe baby in a lukewarm or cool bath, as long as they don’t have a fever. (A cool bath is soothing when baby has a viral rash. But it can cause baby to shiver if they have a fever, which may make the fever worse.)
- During baby’s baths, use mid unscented cleanser, avoid scrubbing, and make sure to pat baby’s skin dry. This will help you make sure you don’t irritate the rash.
- Dress baby in loose clothing.
- Make sure that baby gets plenty of rest and stays hydrated.
- If baby has an itchy rash, cover the rash areas to keep baby from scratching. This way, the rash won’t get infected.
When to see a doctor about baby’s viral rash?
Usually, viral rashes (and the conditions associated with them) aren’t serious, although the conditions that cause them can be more serious if your baby’s immune system is already compromised.
Here’s when you should see your pediatrician about baby’s viral rash:
- You aren’t sure what’s causing the rash, and you’d like a diagnosis
- You’d like to know if it’s okay to give a medicine or use a topical treatment for the rash
- Baby already has a compromised immune system and you’re concerned
- It seems like the rash causes pain
- Baby has a fever along with the rash (as usually, rashes come after the fever)
- Baby seems very lethargic
- Baby isn’t drinking enough fluids (breastmilk/formula/water)
- It looks like baby is bruised along with the rash
- You’ve applied pressure to the rash with the bottom of a clear tumbler, and it didn’t lighten (this could indicate bleeding under the skin, which requires immediate medical attention)
- It’s been a few days, and the rash still hasn’t improved
How do doctors diagnose viral rashes?
Your child’s doctor will diagnose a rash by checking baby’s health history (including vaccine history), as well as what the rash looks like. They might also consider what season it is, as some viral infections are more common at different times of the year. In addition, they’ll make sure the symptom patterns don’t match a different rash-causing condition.
Is it a viral rash or another condition?
Viral rashes may look similar to rashes caused by other types of conditions, including food allergy hives. Here’s how to tell the difference between viral rashes and rashes that have other causes.
Food Allergy Hives
Food allergy hives (also called food allergy rashes) are raised, usually rounded bumps that are very itchy. They appear when someone’s immune system over-defends the body against foods they are allergic to.
Hives could appear anywhere on the body. On babies with lighter skin, hives appear red in color, and have a red flare around them. On babies with darker skin, hives will be dark red or the color of baby’s skin.
Like other food allergy symptoms, food allergy hives appear seconds to minutes after someone eats a food they are allergic to, and almost always within two hours. Hives on one area of the body indicate a mild reaction. But if food allergy hives spread all over the body, this is a sign of a severe allergic reaction --- and your baby will need an EpiPen injection and medical attention.
Keep in mind that a fever is not a food allergy symptom. Viral rashes usually appear a few days after a fever. Meanwhile, food allergy rashes appear without warning, right after someone eats a “problem” food. And while viral rashes last for a few days, food allergy hives usually clear up within several hours to a day.
Baby acne looks very similar to teen and adult acne. It appears as hard red bumps (pimples), sometimes surrounded by small red inflamed areas of the skin. There may also be whiteheads on the bumps --- again, similar to teen and adult acne. Baby acne will last anywhere from a few days to a few months (much longer than a viral rash will last). It usually appears on the face, neck, back, or upper chest. No other symptoms appear alongside it --- it’s not caused by a viral infection, and doesn’t follow a few days after a fever.
Heat rashes develop as a response to very hot weather, and usually develop on the most heat-prone areas of baby’s body (including the face, wrists, armpits, other parts of the arms, and legs.) They look similar to baby acne. Heat rashes appear on their own, without any other symptoms. You’ll usually be able to trace them to a hot day --- they will never be connected with a fever that happened a few days prior.
Eczema (atopic dermatitis) is a chronic, usually lifelong condition with no cure. It causes baby’s skin to develop a dry, rough, flaky, itchy, and sometimes red rash. When baby’s skin is exposed to certain irritants, their eczema will flare up (become worse). Eczema is almost always itchy, while most viral rashes aren’t itchy. It looks more “scaly” than “spotty.” And eczema is never raised, like some viral rashes are.
Reducing The Risk Of Viral Rashes
How to reduce the likelihood that your little one will catch a virus and develop a viral rash? Keeping their immunizations up to date is crucial. As soon as your baby is old enough for the measles/mumps/rubella vaccine and chicken pox vaccine (around 1 year of age), these immunizations are the most effective way to reduce your baby’s risk of exposure to certain viruses.
But what about other viral infections? And what about before your baby is old enough for the vaccines? Sometimes, there’s nothing you can do to prevent exposure. But frequently washing baby’s hands (and your own hands) is the best way to reduce baby’s risk of exposure. And if baby does show any virus symptoms like the ones we covered above, keep them home and limit their exposure to others, so others don’t become infected.
All health-related content on this website is for informational purposes only and does not create a doctor-patient relationship. Always seek the advice of your own pediatrician in connection with any questions regarding your baby’s health.
These statements have not been evaluated by the Food and Drug Administration. Products are not intended to diagnose, treat, cure or prevent any disease.