Several conditions, including chickenpox, fifth disease, and roseola, can cause fever with a rash in a child.

These viral illnesses can be unpleasant, but they usually go away on their own. Less commonly, however, a sudden rash with a fever might signal something more serious, such as a severe drug reaction.

Parents or caregivers should always consult a doctor when a child has a fever with a rash, especially if the child is very ill or their symptoms get rapidly worse.

Numerous conditions can cause fever and a rash in children. They include:

Fifth disease

A virus called parvovirus B19 causes a common childhood infection called fifth disease. Doctors may also call it “slapped cheek” disease because the rash often causes a red or darker patch on the cheek. The medical term is erythema infectiosum.

The infection usually begins about 2 weeks after exposure to the virus, with symptoms such as headaches, fever, and a runny nose. A child may then develop a rash that begins on their face and spreads. Some children also develop joint pain that can last 1–3 weeks.

Usually, the rash comes after the fever resolves, not at the same time.

Fifth disease usually clears on its own. It can sometimes cause complications, such as anemia, but these are rare. The condition is contagious for as long as the child has a fever. Once the rash begins, they are no longer contagious.

Learn more about fifth disease here.

Roseola

A type of virus in the herpesvirus family causes roseola, producing a rash that presents as small flat spots or tiny bumps. A halo of slightly lighter or paler skin may surround some of the bumps.

Children with roseola usually get a fever and runny nose, and they may be irritable and tired. The rash often starts on the face but eventually covers the entire body.

The fever and rash rarely occur at the same time. Instead, the roseola rash typically appears soon after the fever disappears.

Roseola typically goes away on its own within a few days, and there is no specific treatment.

Learn more about roseola here.

Chickenpox

A virus called varicella-zoster causes chickenpox. Most children now get the chickenpox vaccine, which is very effective, but some will still get the virus. Children who get chickenpox after having had the vaccine tend to experience a more mild form of the illness.

Chickenpox may begin with a fever, exhaustion, irritability, or a headache. The rash tends to appear within a day or two, presenting as many tiny, fluid filled blisters all over the body. The blisters itch and may crack open and bleed.

Most people get better in about a week.

Learn about home remedies for relieving the symptoms of chickenpox here.

However, children with serious medical conditions or a weakened immune system may get very sick.

Learn more about chickenpox here.

Scarlet fever

Scarlet fever results from a group A Streptococcus infection, such as strep throat. Strep is a bacterial infection, and people usually get sick within a few days of infection.

A scarlet fever rash may affect the chest, neck, or groin.

Learn more about scarlet fever rash here.

If a child has a sore throat and a rash, or they get a rash after a sore throat goes away, they may have scarlet fever. Most kids also get a fever and may have flushed-looking cheeks.

Antibiotics can treat scarlet fever. However, in some children, the infection becomes very severe. For this reason, if the child is not better in a few days, it is important to speak to a doctor.

Learn more about scarlet fever here.

Hand, foot, and mouth disease

Hand, foot, and mouth disease (HFMD) commonly affects babies and children under 5 years old. Children usually get a fever and flu-like symptoms, such as aches and pains. Within a few days, they develop sores around their mouth and on their hands or feet.

The virus that causes HFMD is highly contagious and may spread to parents or caregivers. In most children, symptoms are mild and go away within 7–10 days.

Learn more about HFMD here.

Meningococcemia

Meningococcemia is a rare but dangerous blood infection. Bacteria called Neisseria meningitidis, also known as meningococcus, cause the infection.

Meningococcal disease is most common in children under the age of 1 year. Early symptoms include fever, joint and muscle pain, rapid breathing, fatigue, and vomiting.

Occasionally, tiny red, purple, or brown dots called petechiae can appear on the skin at the same time. More often, at a later stage, a dark rash will appear.

Meningococcemia is dangerous and can cause severe complications, such as septic shock. Immediate medical treatment with antibiotics is essential. Anyone who suspects that they or a child has a meningococcal infection should seek medical attention right away.

Learn more about meningococcemia here.

Cellulitis

Cellulitis is a serious bacterial skin infection that affects the deeper layers of the skin. It usually appears following an injury to the skin, such as a sting, bite, or wound. However, some people get cellulitis even when they do not have a visible skin injury.

Cellulitis causes very tender skin around the area of the injury. The skin is usually red or discolored and swollen. There may be streaks coming out of the rash, indicating that the infection is spreading. Some people with cellulitis develop a fever. A fever with cellulitis may signal a severe infection, which warrants immediate medical care.

Antibiotics are almost always necessary to treat cellulitis.

Learn more about cellulitis here.

Drug reaction

Sometimes, a rash warns of a drug reaction. If fever occurs alongside a drug rash, it often has a separate cause — for example, an underlying infection.

In rare cases, a child might develop a rash a few days after a fever, in reaction to a medication. A severe skin reaction called Stevens-Johnson syndrome can damage the skin and organs, and most children who get it must stay in the hospital.

When a rash and fever appear only after taking medication, this may be an emergency, so it is important to call a doctor.

Most rashes that occur with a fever happen because of viral illnesses. Antibiotics and other drugs cannot treat viruses. Instead, doctors focus on controlling the symptoms. They might recommend:

  • resting as much as possible
  • drinking lots of fluids
  • taking medication to lower a fever

Depending on the cause of the symptoms, in severe cases, a child might sometimes need to stay in the hospital.

Antibiotics can treat cellulitis and similar skin infections, as well as strep infections. Occasionally, a viral rash becomes infected, especially if a child scratches it a lot. If this happens, a child might need antibiotics. Antibiotics will get rid of the infection, but they will not treat the rash.

As quitting an antibiotic early can make an infection worse or even cause drug-resistant infections, it is important to talk to a doctor before stopping any medication. Parents and caregivers should never just assume that a drug has caused a child’s rash.

Parents and caregivers should call a doctor any time a child gets a rash with a fever. They should take the child to the emergency room if:

  • a child seems very ill and has a rash that has streaks coming out of it
  • the child’s skin starts peeling off
  • the rash covers most of the child’s body and appears a few days after taking a new medication
  • a child has trouble breathing, or any part of their body swells

Most rashes in children are ultimately harmless. A child might feel itchy or sick for a few days before gradually feeling better.

If a child suddenly gets worse, seems very ill, or gets a fever after taking a new medication, it is important to take them to see a doctor immediately.