Scarlet Fever: Symptoms in Children, Treatment and How Long It’s Contagious

Scarlet fever sounds old-fashioned, but it never went away. Cases rise every winter and spring, mostly in school-age children. The good news: it is easy to treat with antibiotics. The catch: you have to recognise it first, because the rash can be easy to miss.

Imagine your seven-year-old comes home from school with a sore throat and a temperature. You think it’s just a cold. Two days later you notice a rough rash on their chest that feels like fine sandpaper, and their tongue looks bright red and bumpy, like a strawberry. That combination is the classic picture of scarlet fever, and it means it’s time to call your doctor or nurse.

What causes scarlet fever?

Scarlet fever is caused by group A streptococcus, the same bacteria behind strep throat. It spreads through coughs, sneezes and close contact, and by touching surfaces and then the mouth or nose. It is most common in children aged about 5 to 15, and less common in children under 3. Adults can catch it too.

Symptoms to look for

• First: sore throat, fever of 38°C (100.4°F) or above, headache, swollen glands in the neck, sometimes tummy ache or vomiting
• 12 to 48 hours later: a rash of tiny bumps, usually starting on the chest and tummy and spreading. It feels rough, like sandpaper.
• On darker skin the redness can be hard to see, but you can still feel the rough texture
• “Strawberry tongue”: a white coating at first, then a red, swollen, bumpy tongue
• Flushed cheeks with a paler area around the mouth
• Peeling skin on the fingertips, toes and groin as the rash fades, about a week later

How scarlet fever is treated

A doctor or nurse may diagnose it by looking at the throat and rash, or confirm it with a throat swab. Treatment is antibiotics, usually penicillin or amoxicillin, typically for 10 days. Other antibiotics are available if your child is allergic to penicillin.

• Finish the full course, even when your child feels better after a couple of days. Stopping early raises the risk of the infection coming back or causing complications.
• Give plenty of fluids and soft, cool foods if swallowing hurts.
• Use paracetamol (acetaminophen) or ibuprofen for pain and fever, following the dose for your child’s age or weight on the pack.
• Calamine lotion or an antihistamine suitable for the child’s age may ease itching. Ask a pharmacist.

But how long is scarlet fever contagious?

People can spread it before the rash appears. Once antibiotics start, the risk drops quickly. Advice differs a little by country:

• The US CDC says children can return once they have no fever and have had at least 12 hours of antibiotics, with 24 hours considered in some settings such as outbreaks or healthcare work.
• The UK’s NHS advises staying off school, nursery or work until 24 hours after the first dose of antibiotics.
• Without antibiotics, a person can stay infectious for much longer, often two to three weeks.

Check your school’s or employer’s rules, wash hands often, and don’t share cups, cutlery or towels.

When to get urgent help

Rarely, group A strep can cause serious infection. Get urgent medical help if your child:

• Has difficulty breathing, or the skin between the ribs pulls in with each breath
• Is very drowsy, floppy or hard to wake
• Has a fever that keeps going despite medicine, or a fever above 38°C in a baby under 3 months
• Has a painful, red, swollen area of skin that is spreading, or severe pain in one limb
• Is not drinking, or has had no wet nappy or pee for 12 hours or more

Sources: US Centers for Disease Control and Prevention (Scarlet fever), NHS (Scarlet fever), World Health Organization. This guide is for general information and does not replace advice from your own nurse, doctor or pharmacist.