How to tell the difference between roseola and measles rash

Roseola, also known as roseola infantum, sixth disease, or exanthema subitum, is a viral infection that typically affects children. The human herpesvirus 6 (HHV-6) or human herpesvirus 7 (HHV-7) causes roseola.

The disease is spread through tiny respiratory droplets that people either breathe in or pick up from surfaces they touch.

This disease usually presents in children between the ages of 6–12 months. Children who have this disease experience a high fever, followed by a pink or red rash.

Roseola is a self-limiting viral illness, meaning it will typically go away without any medical attention. Doctors advise treating roseola at home unless the child has seizures or persistent high fever.

Measles is a very infectious disease that killed more than 140,000 people in 2018 globally. A majority of these were children under 5 years old.

The measles virus is a part of the Paramyxoviridae family, and the Morbillivirus genus and people can spread this through direct contact and the air.

People who have measles often experience a high fever and a rash. Measles carries a higher risk of complications in children under 5 years old, or adults over 30 years.

Both roseola and measles may look similar in appearance as they usually present with a maculopapular rash. However, roseola rash is usually more pink-red, while measles rash is more red-brown.

While it may be easy to confuse the two, other features help to differentiate between roseola and measles.

The rash from roseola begins in the torso and spreads out, while the measles rash starts on the face and moves downwards.

Additionally, children with roseola usually appear well, while those with measles typically look and behave as if they are unwell.

Roseola

Roseola shows a unique disease progression in that the rash appears shortly after the fever ends.

The fever will last roughly 3–5 days, and, as it subsides, children will experience small pink-red bumps and rashes, approximately only 2–5 millimeters across. Sometimes, a pale halo will appear around these areas.

The rash usually starts on the torso and spreads to the neck, face, legs, and arms within 24 hours.

The rash is usually not itchy and turns white under pressure. The rash usually disappears after 1–2 days.

Measles

Similarly to roseola, the measles rash appears roughly 3–5 days after symptoms begin.

In the case of measles, however, the fever symptoms do not subside and instead accompany the rash.

While the measles rash is also not usually itchy, it consists of distinct red spots that start along the hairline and then spread downwards to the neck, torso, limbs, and feet.

Some people may have small, raised bumps, and these may merge as the rash spreads.

A defining characteristic of measles is that the fever disappears when the rash stops spreading.

In addition to fever and rash, both diseases may also include other symptoms, as follows:

Roseola

Children with roseola may also experience:

• a high fever that may be above 104^oF,
• conjunctivitis
• swelling around the eyes
• malaise
• irritability
• loss of appetite
• diarrhea
• cough
• Nagayama spots, bumps in the mouth between the soft palate and uvula
• swelling of the inner ear
• swelling of the lymph nodes

Roseola does not tend to have many complications. However, around 15% of children with roseola experience seizures due to the high fever. The symptoms of a seizure include:

• fainting
• twitching or jerky movements
• a potty trained child soiling themselves
• irritability

Measles

People with measles will also experience a cough, conjunctivitis, and a runny nose along with the rash and fever.

Some children will experience Koplik spots 2–3 days after symptoms begin. Koplik spots are tiny white spots that appear in the mouth.

Measles can be fatal in some cases. Most people who die from measles complications are children under 5 years old, or adults over 30 years old.

Some serious complications include:

• blindness
• brain swelling
• severe diarrhea and dehydration
• ear infections
• pneumonia

Roseola resolves relatively quickly. The fever lasts 3–5 days, followed by the rash. The rash lasts around 2 days.

Measles symptoms can last up to 2 weeks after a person is infected. People who do not experience any complications usually recover a week after the appearance of the rash.

People may be able to treat both diseases in a similar way. Some treatment options include:

Roseola

Doctors do not have a specific treatment for roseola. They recommend rest and fluids, with painkillers such as acetaminophen, or anti-inflammatories such as ibuprofen to control the fever. However, unless a doctor advises, carers must not give aspirin to a child with fever due to the risk of Reye’s syndrome.

Measles

As with roseola, there is no specific treatment for measles. People can use painkillers and anti-inflammatories to control the fever and drink lots of fluid to prevent dehydration.

The World Health Organization (WHO) recommend daily doses of vitamin A for 2 days for those who are malnourished or immunocompromised.

Measles is a preventable disease as there is a safe, inexpensive, and effective vaccine.

While it may be possible to treat symptoms of both diseases at home with rest, painkillers, and fluid, seeing a doctor as soon as anyone starts showing symptoms of measles is important.

If a person displays persistent high fever or rash, it is advisable to seek medical attention. Emergency medical care is necessary if a child has a febrile seizure.

Both roseola and measles are illnesses that commonly affect children. Both of these diseases present with a rash and fever, however, their disease progression is different.

The rashes of both diseases vary in color, and roseola rash starts in the torso and spreads out, while measles rash begins in the face and spreads downwards.

Neither of these diseases has a specific treatment. Doctors instead advise that people treat the fever with anti-inflammatories and painkillers, and drink lots of fluids.

It is essential to seek medical attention if a very high fever occurs, or if there are any signs of complications.