Scarlet fever is due to a throat infection caused by a germ (bacterium) called streptococcus, usually group A streptococcus. It causes a rough-feeling red rash, sore throat, fever and sometimes other complications
Scarlet fever is most common in children aged less than 10 years, with 4-year-olds most likely of all to catch it. 87% of cases in the UK are in children under 10 years. Although adults can get scarlet fever, this is very unusual. However, the symptoms and treatment are the same as for children.
Scarlet fever used to be very common in the 1800s and early 1900s because of overcrowding and poor living conditions. In those days it was the leading cause of death in children. But it got much rarer as general health measures improved. There have been some recent outbreaks in the UK, usually in schools, but antibiotics can now treat scarlet fever very effectively.
What are the symptoms?
- High temperature (fever).
- Sore throat.
- Redness of the tongue with tiny white spots (this occurs around the same time).
- Sometimes swelling of the tongue a few days later.
- A red, rough-feeling rash on their chest, tummy and cheeks - it feels a bit like sandpaper.
Read more detail on the symptoms of scarlet fever.
What causes it?
A germ called group A streptococcus is the most common cause of scarlet fever. The scarlet fever rash occurs when the streptococcal germs (bacteria) release poisons (toxins) that make the skin go red. The toxins get into the blood from the infected throat.
Read more about the causes of scarlet fever.
Are there any tests?
Scarlet fever is usually diagnosed by the symptoms, especially if you have the typical rash.
Sometimes your doctor will take a sample (swab) from your throat to be tested for streptococcus. A blood test is also sometimes done which can confirm that you have this infection.
Find out more about tests for scarlet fever.
What is the treatment?
Treatment is to speed recovery and to prevent possible complications.
Antibiotics for scarlet fever
A 10-day course of phenoxymethylpenicillin is usually advised. Other antibiotics are advised if you are allergic to penicillins. Symptoms usually improve in a few days but it is important to finish the course of antibiotics. This makes sure all the germs (bacteria) are killed and reduces the chance of complications.
Find out more about treatment of scarlet fever.
What are the possible complications?
If the infection spreads, it can sometimes cause complications, including ear infection, throat abscess, sinus infection, pneumonia or even meningitis and brain abscess. However, most children will recover within a few days, without complications.
If antibiotics are not used, the scarlet fever will go away by itself. However, this can have serious consequences for the body. The infection can affect the kidneys, even years later, causing something called glomerulonephritis. Or it can affect the heart, again even many years later, causing rheumatic fever. That's why you should always make sure your child takes their whole course of antibiotics.
Read more about complications of scarlet fever.
What is the outlook for people with scarlet fever?
In the past, scarlet fever used to be a very serious condition. Fortunately, nowadays for most cases, scarlet fever is a mild, self-limiting illness. Most children will recover fully within a week or so, even without treatment. (However, it is best to have treatment - see above.)
Deaths from scarlet fever are now extremely rare in the western world.
Is scarlet fever infectious?
Yes. Coughing, sneezing and breathing out the germs (bacteria) can pass it on (be infectious) to others. Scarlet fever can even be passed on by sharing towels, baths, clothes or bed linen with a person who has been infected.
It takes 2-4 days to develop symptoms after being infected. You should keep children with scarlet fever off school and away from others, for 24 hours after starting antibiotics.
Once a person has had scarlet fever, they are very unlikely to get it again. This is because they become immune to the bacteria. However, it is possible to have repeated attacks, as there are different types of streptococcal bacteria which cause the infection.
The recent outbreak of scarlet fever has sometimes occurred in schools where there is also an outbreak of chickenpox. If you have a child who has recently had chickenpox and then gets scarlet fever you need to watch out for signs of serious infection. These may include joint pains, high temperature (fever) and persistent skin infection.
There is no evidence that catching scarlet fever when pregnant will put your baby at risk
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Further reading & references
- Scarlet fever: guidance and data; Public Health England
- Interim guidelines for the public health management of scarlet fever outbreaks in schools, nurseries and other childcare settings; Public Health England, 2014 (archived content)
- Wong S et al; Emerging Microbes and Infections, Nature.com, 2012
- Feverish illness in children - Assessment and initial management in children younger than 5 years; NICE Guideline (May 2013)
- Scarlet fever; NICE CKS, May 2010
- No authors listed; Varicella, herpes zoster and nonsteroidal anti-inflammatory drugs: serious Prescrire Int. 2010 Apr 19(106):72-3.
- No authors listed; Sixty seconds on . . . scarlet fever. BMJ. 2016 Mar 23 352:i1658. doi: 10.1136/bmj.i1658.
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