A fever is not a disease but a sign that the body's immune system is fighting an infection. The body raises its core temperature to fight off the invading bacteria or viruses.
Children aged 1–3 years old, generally referred to as toddlers, often get illnesses because:
- their immune systems have not yet fully developed
- they have increased exposure to germs from other children, especially in day care or preschool
- they tend to put their hands or objects in their mouths
Fever usually goes away once the illness passes. However, toddlers sometimes develop a rash following a fever. Although this is rarely severe, it is important to see a doctor immediately.
In this article, we look at the possible causes of a rash after fever in toddlers, what to do about it, and when to see a doctor.
Several common childhood illnesses can cause a rash after fever. Most are not serious, but some do require medical treatment, so it is essential to discuss these symptoms with a doctor.
Common causes of post-fever rash in toddlers include:
Roseola infantum may cause a post-fever rash.
Roseola infantum, which is also called roseola or sixth disease, is a viral infection. Babies and toddlers pass on the virus through saliva, coughing, and sneezing.
Roseola may cause a sudden, high fever of 102–105°F that lasts for 3–6 days. Some children are active and comfortable with no other symptoms during this stage of the illness, but others may also experience:
- decreased appetite or unwillingness to eat
- eye swelling or conjunctivitis, also known as pink eye
- a cough
- a runny nose
- swollen lymph nodes
- sleepiness or irritability
Typically, the symptoms of roseola go away suddenly on the sixth or seventh day of illness. After these symptoms have cleared up, the rash appears.
In most cases, the roseola rash:
- consists of small pink spots, about 2–5 millimeters (mm) wide
- may be slightly raised or flat
- starts on the trunk and may spread to the arms, neck, and face
- does not itch or hurt
- disappears when pressed, which is known as blanching
- fades after 1–2 days
The incubation period for roseola is 7–14 days, which means that symptoms may not appear until 1–2 weeks after becoming infected. Antibiotics do not work against roseola, but extra fluids and fever-reducing medicine can relieve symptoms.
Parents and caregivers should keep children with roseola out of school or day care until they have been free of fever for 24 hours without the use of medication. The rash from roseola is not contagious.
During a febrile seizure, the child may:
- lose consciousness
- start shaking their arms and legs uncontrollably
- become stiff
- roll their eyes
- wet or soil themselves
- froth at the mouth
Febrile seizures generally only last a few minutes. According to the National Institute of Neurological Disorders and Stroke, there is no evidence that short febrile seizures cause brain damage. Most children will recover without any problems.
However, the parent or caregiver should immediately call an ambulance if:
- it is the child's first febrile seizure
- the seizure lasts longer than 5 minutes
- the child has a stiff neck, is vomiting excessively, or is extremely lethargic
During the seizure, it is vital to:
- remain calm and time the length of the seizure
- carefully place the child in a safe location to protect them from accidental injury
- position the child on their side or front to prevent choking
- carefully remove any objects from the child's mouth
A person may contract scarlet fever through contact with infected skin lesions.
Infected children can pass on the bacteria through:
- coughing and sneezing
- sharing food or drinks
- letting other people touch a skin lesion, where there is a skin infection
Symptoms of scarlet fever may include:
- a temperature of 101°F or higher
- red rash that starts on the neck, underarms, or groin area and spreads across the body
- red, sore throat
- white coating or red bumps on the tongue
- redness in skin creases, such as under the arms and inside the elbows and inner thighs
- a headache
- body aches
- nausea, stomach ache, or vomiting
The rash from scarlet fever feels rough like sandpaper. It usually appears 1–2 days after the fever starts but can present up to 7 days later.
The area around the mouth usually remains pale, even if the rest of the face looks red. After the rash has faded, the skin may peel.
A child with symptoms of scarlet fever should see a doctor as soon as possible. In rare cases, group A strep infections can cause severe complications, such as heart or kidney problems.
Doctors treat scarlet fever with antibiotics. A child may return to school or day care once they have been taking antibiotics for at least 24 hours.
Hand, foot, and mouth disease
Hand, foot, and mouth disease (HFMD) is common in children under 5 years old. Several different viruses can cause this illness, and children can pass on the infection through:
- coughing and sneezing
- fluid from blisters
HFMD often starts with a fever, but it may also cause a sore throat, lack of appetite, and malaise.
After about 1–2 days, sores and a rash may appear. The telltale signs of HFMD include:
- sores in the back of the mouth that are small initially but turn into painful blisters
- flat, red spots on the palms of the hands or the soles of the feet
- flat, red spots or blisters on the buttocks or groin
Some toddlers might get all of these symptoms, while others may only get mildly sick without any other problems. A parent or caregiver should get advice from a doctor on when a child with scarlet fever should return to school or day care.
Although most cases of HFMD resolve on their own, the sores can be painful. If a child is unable to eat or drink, there is a risk of dehydration. Children who are not eating or drinking or who seem very ill should see a doctor.
Fifth disease, known medically as erythema infectiosum, is a viral infection that commonly occurs in toddlers. Parvovirus B19 is the virus responsible for the infection, which spreads easily through coughing and sneezing.
Symptoms of fifth disease may include:
- a headache
- a runny nose
Fifth disease is sometimes called slapped cheek syndrome because the rash causes the cheeks to appear red. Some toddlers may get a red, blotchy rash on their trunk, buttocks, arms, and legs a few days after the redness becomes apparent in the cheeks.
The rash may cause itching and tends to form a lacy pattern as it starts to fade. It can last for several weeks.
Most children recover from fifth disease without any problems. However, both children and adults with weakened immune systems can develop long-term complications.
As it is a viral illness, antibiotics are not effective against fifth disease. Plenty of fluids, rest, and pain relievers may be beneficial.
Usually, children can go back to school or day care once they have been fever-free for at least 24 hours. The rash is not contagious.
What to do about a rash after fever
A pharmacist can offer advice about medication for children.
If a toddler is uncomfortable, medications that reduce pain and fever can relieve symptoms. Acetaminophen or ibuprofen are standard choices and are available over the counter (OTC).
When giving medication to a child:
- always follow the directions on the packaging carefully
- be sure to use the correct amount for the child's age and weight
- if in doubt, check with a medical professional first
Encourage the child to drink plenty of fluids. Popsicles or children's electrolyte drinks may be helpful if the child does not want water.
When to see a doctor
Fevers in toddlers are often due to illnesses that get better on their own. However, parents and caregivers should observe young children when they get a fever, rash, or other symptoms of an illness.
Call a doctor if a child of any age gets a rash after fever, or if the child is:
- younger than 3 months of age and has a rectal temperature of 100.4°F or higher
- aged 3–6 months and has a temperature of 102°F or higher
- over 6 months of age and has a fever of 103°F or higher
This is essential even if the child does not seem unwell.
Fever and rashes are common in toddlers. Most of the time, the child will recover without any long-term problems. However, it is important to monitor symptoms closely.
If symptoms become worse or do not go away, see a doctor. Parents and caregivers who have any concerns about a child's illness should speak to a doctor.