Rash with fever in children, from roseola and HFMD to measles

Most rashes that come with fever in children are caused by common viruses and settle by themselves. A few rashes are dangerous and need hospital care at once. The most useful home check is the glass test: a rash that does not fade when you press a clear glass on it needs urgent medical help. Below, Dr Dutta goes through the common rashes one question at a time.

My child had a fever and now a rash. Is it roseola?

If a baby or toddler had a high fever for a few days, seemed fairly well, and then got a pink rash just as the fever went away, roseola is the likely cause.

Roseola is caused by human herpesvirus 6 (HHV-6). In a US study following children from birth, 40 percent had caught HHV-6 by 12 months and 77 percent by 24 months.¹ Most infections caused symptoms such as fever and fussiness, but the classic roseola rash appeared in only a minority.¹ The rash is small, pink, flat or slightly raised spots, mostly on the chest, back and neck. It does not itch much and fades in 1 to 2 days.

Is roseola serious, and do fits happen?

Roseola is almost always mild. In the study above, none of the 81 children whose infection could be timed had a seizure (fit).¹ A high fever can still occasionally trigger a febrile seizure in young children.

No medicine treats the virus. Give paracetamol for discomfort, offer fluids, and dress your child lightly. Once the rash appears, the child is usually feeling better. Any fit, even a short one, needs a doctor's review, especially if it is the first one.

What is hand, foot and mouth disease?

HFMD is a common viral illness in young children. It causes fever, painful mouth ulcers, and small spots or blisters on the hands, feet and nappy area.

It is caused by enteroviruses, a family of viruses that spread through saliva, blister fluid and stool. Most children recover in about a week without any problem. Rarely, some virus types cause complications affecting the brain, which is why a very sleepy or jerky child needs urgent care.² Outbreaks are common in Indian playschools, often around the monsoon.

How long is hand, foot and mouth disease contagious?

A child is most infectious in the first week of illness, but the virus can stay in the stool for several weeks after recovery.

In one small study, children kept passing the virus in their stool for 7 to 11 weeks, and in the throat for 1 to 2 weeks.³ That is why careful handwashing after nappy changes matters long after the spots have gone. In the UK, a child who feels well enough does not need to stay off school.⁴ In practice, Dr Dutta suggests keeping a child home while they have fever or drooling with mouth sores, because many Indian schools ask for this.

How can I help my child eat and drink with HFMD?

The biggest risk with HFMD is dehydration because the mouth hurts. Keep fluids going even if your child eats very little for a few days.

• Offer cool, soft foods: curd, khichdi, mashed banana, suji, cold milk.
• Avoid spicy, salty or sour foods such as pickles and citrus.
• Give paracetamol before meals to ease pain.
• Count wet nappies. Far fewer than usual, or an older child who has hardly passed urine all day, needs a doctor.

Chickenpox: what should I do at home?

Chickenpox usually needs only home care: paracetamol for fever, plenty of fluids, short nails, loose cotton clothes, and calamine lotion for the itch.

The spots start as red bumps, turn into fluid-filled blisters, then crust over in crops for about a week. Keep your child away from newborns, pregnant women and anyone with a weak immune system. Babies, teenagers and children with eczema or low immunity can get sicker, so speak to your doctor early for them. Antiviral medicine is sometimes advised in these groups.

What should I avoid when my child has chickenpox?

Avoid ibuprofen and other painkillers of that type (NSAIDs), and never give aspirin. Use paracetamol instead.

A large UK study found that children with chickenpox who were taking NSAIDs had about 5 times the rate of severe skin and soft tissue infections, such as cellulitis and abscess. Paracetamol did not carry this risk.⁵ Aspirin given during chickenpox or flu is linked to Reye's syndrome, a rare illness that damages the liver and brain.⁶ Also avoid applying home pastes or turmeric to open blisters, and do not prick them.

Is there a vaccine for chickenpox?

Yes. Two doses of the chickenpox (varicella) vaccine give strong protection.

A Cochrane review found that two doses prevented about 95 percent of chickenpox cases over 10 years of follow-up.⁷ In India this vaccine is not yet part of the free government schedule, but it is available privately. Ask your paediatrician about timing.

What are the signs of measles?

Measles starts with high fever, cough, runny nose and red, watery eyes. A few days later a red, blotchy rash begins on the face and behind the ears, then spreads down the body.⁸

Tiny white spots inside the cheeks may appear before the rash. The rash tends to come a few days after the cold-like symptoms begin, and it lasts for several days.⁸ Measles is very contagious from about 4 days before to 4 days after the rash appears.⁸ Complications include pneumonia, diarrhoea, ear infection, blindness and brain swelling, and they are most common in children under 5 and in children who are poorly nourished.⁸

Why does measles vaccination matter so much?

The measles vaccine is safe and very effective, and two doses protect almost every child.

A Cochrane review found that one dose prevented about 95 percent of measles cases and two doses about 96 percent.⁷ By WHO's estimate, measles vaccines saved close to 59 million lives from 2000 to 2024.⁸ In India, measles-rubella (MR) vaccine is given free under the government programme. WHO advises the first dose at 9 months where measles is common, with a second dose later.⁸ Please do not skip or delay it.

Does vitamin A help a child with measles?

Yes. WHO advises two doses of vitamin A, on two days in a row, for every child under 5 with measles.⁸

A Cochrane review found that two doses were linked to fewer deaths in children under 2 with measles.⁹ Your doctor will give the right dose for age.

Which rash with fever is an emergency?

A rash that does not fade when pressed, together with fever or an unwell child, is an emergency. It can be a sign of meningitis, a serious infection around the brain.¹⁰

Use the glass test. Roll the side of a clear tumbler firmly over the spots. Spots that stay visible through the glass mean you should go to hospital at once.¹⁰ The spots may start as tiny red or purple pinpricks and can be harder to see on darker skin, so check paler areas such as the palms, soles and inside the eyelids. Do not wait for a rash. In a UK study of children with meningococcal disease, early signs such as leg pain, cold hands and feet, and pale or mottled skin appeared hours before the classic rash.¹¹

Hives: is it an allergy or an infection?

In young children, hives (raised, itchy, pink welts that move around within hours) are most often triggered by a viral infection, not by an allergy.

In a French study of babies and toddlers with sudden hives, an infection was the cause in about 81 percent, and food in about 11 percent.¹² If hives started soon after a new food or medicine, tell your doctor. Hives with swelling of the lips or tongue, breathing difficulty or vomiting is anaphylaxis (a severe allergic reaction) and needs emergency care. Otherwise, an antihistamine prescribed by your doctor eases the itch.

What is slapped cheek (fifth disease)?

Slapped cheek (fifth disease) is a mild viral illness that causes bright red cheeks, followed by a lacy pink rash on the arms and legs.

It is caused by parvovirus B19. Children are infectious before the rash appears, so once the rash shows, they no longer need to stay off school.⁴ Tell any pregnant woman who was in close contact, and children with blood disorders such as thalassaemia or sickle cell disease should see a doctor.

What is impetigo and how is it treated?

Impetigo is a skin infection caused by bacteria. It causes sores or blisters that burst and form honey-coloured crusts, often around the nose and mouth.

A Cochrane review found antibiotic creams such as mupirocin or fusidic acid work as well as, or better than, antibiotics by mouth for limited impetigo.¹³ Wide-spread impetigo may need oral antibiotics. Keep nails short and towels separate. UK advice is to keep children off school until sores have crusted and healed, or for 48 hours after starting antibiotics.⁴

Can my child go to school with a rash?

It depends on the cause. Your child should stay home with any fever, and until a doctor knows what the rash is.

• Chickenpox: stay home until all spots have crusted over, usually about 5 days after they appear.⁴
• Measles: keep your child home for a minimum of 4 days after the rash first shows.⁴
• Impetigo: until sores crust and heal, or 48 hours after starting antibiotics.⁴
• Slapped cheek and roseola: back once well and fever-free.
• Hand, foot and mouth: back when well and fever-free, with good handwashing.

When should I take my child to a doctor or hospital?

Go to hospital immediately, or see a doctor the same day, if your child has:

• A rash that does not fade under a glass, with or without fever.
• Fever in a baby under 3 months, whatever the rash.
• Cold hands and feet, leg pain, pale or blotchy skin with fever.
• Unusual drowsiness, stiff neck, fits, or jerky movements.
• Fast or hard breathing, or a cough with measles.
• Signs of dehydration: very few wet nappies, dry mouth, no tears.
• Chickenpox spots that turn red, hot, swollen and painful.
• Swelling of lips, tongue or face, or breathing difficulty with hives.
• Fever lasting more than 5 days, or red eyes, cracked lips and swollen hands with rash.