Scarlet fever is a bacterial illness that mainly affects children. It causes a distinctive pink-red rash.
The illness is caused by Streptococcus pyogenes bacteria, also known as group A streptococcus, which are found on the skin and in the throat.
Generally, scarlet fever is much less common than it used to be but in recent years there have been a number of significant outbreaks.
For example, in 2014 Public Health Wales saw very high numbers of cases reported in Wales, with 1382 cases reported for the whole year. Figures published by Public Health England show that from September 2013 to March 2014 there were 2,830 cases of scarlet fever. For the same period in 2014/15 a total of 5,746 cases were recorded. The reason for recent increase is unclear.
It’s important to be aware of the signs and symptoms of scarlet fever so that early treatment with antibiotics can be given.
Scarlet fever symptoms
Scarlet fever usually follows a sore throat or a skin infection, such as impetigo, caused by particular strains of streptococcus bacteria.
Initial symptoms usually include a sore throat, headache and a high temperature (38.3C/101F or above), flushed cheeks and a swollen tongue.
A day or two later the characteristic pinkish rash appears. It usually occurs on the chest and stomach before spreading to other areas of the body, such as the ears and neck.
The symptoms of scarlet fever usually develop two to five days after infection, although the incubation period (the period between exposure to the infection and symptoms appearing) can be as short as one day or as long as seven days.
The rash feels like sandpaper to touch and it may be itchy. On darker skin the rash may be more difficult to see although its rough texture should be apparent.
When to seek medical advice
Scarlet fever usually clears up after about a week, but if you think you or your child may have it, see your GP for a proper diagnosis and appropriate treatment.
Your GP should be able to diagnose scarlet fever by examining the distinctive rash and asking about other symptoms. They may also decide to take a sample of saliva from the back of the throat so it can be tested in a laboratory to confirm the diagnosis.
There's no evidence to suggest that catching scarlet fever when pregnant will put your baby at risk. However, if you're heavily pregnant, tell the doctors and midwives in charge of your care if you've been in contact with someone who has scarlet fever.
How scarlet fever spreads
Scarlet fever is very contagious and can be caught by:
- breathing in bacteria in airborne droplets from an infected person's coughs and sneezes
- touching the skin of a person with a streptococcal skin infection, such as impetigo
- sharing contaminated towels, baths, clothes or bed linen
It can also be caught from carriers – people who have the bacteria in their throat or on their skin but don't have any symptoms.
Who's affected by scarlet fever
Most cases (about 80%) of scarlet fever occur in children under 10 (usually between two and eight years of age). However, people of any age can get the illness.
As it's so contagious, scarlet fever is likely to affect someone in close contact with a person with a sore throat or skin infection caused by streptococcus bacteria. Outbreaks often occur in nurseries and schools where children are in close contact with one another.
The symptoms of scarlet fever will only develop in people susceptible to toxins produced by the streptococcus bacteria. Most children over 10 years of age will have developed immunity to these toxins.
It's possible to catch scarlet fever more than once, but this is rare.
Treating scarlet fever
Scarlet fever used to be a very serious illness, but nowadays most cases tend to be mild.
It can easily be treated with antibiotics. Liquid antibiotics, such as penicillin or amoxicillin, are often used to treat children. These must be taken for 10 days, even though most people recover after four to five days.
It's important to be aware that your child will still be infectious for 24 hours after antibiotic treatment has begun, and therefore they shouldn't attend nursery or school during this period (see below).
Without antibiotic treatment, your child will be infectious for 1-2 weeks after symptoms appear.
Read more about treating scarlet fever.
Complications of scarlet fever
With the right treatment, further problems are unlikely. However, there's a small risk of the infection spreading to other parts of the body and causing more serious infections, such as an ear infection, sinusitis, or pneumonia.
Read more about complications of scarlet fever.
Preventing scarlet fever from spreading
There’s currently no vaccine for scarlet fever.
If your child has scarlet fever, keep them away from nursery or school for at least 24 hours after starting treatment with antibiotics. Adults with the illness should also stay off work for at least 24 hours after starting treatment.
GPs, schools and nurseries should be aware of the current high levels of scarlet fever and inform local health protection teams if they become aware of cases, particularly if more than one child is affected.
Children and adults should cover their mouth and nose with a tissue when they cough or sneeze and wash their hands with soap and water after using or disposing of tissues.
Avoid sharing contaminated utensils, cups and glasses, clothes, baths, bed linen or towels.
Scarlet fever is also sometimes known as scarlatina, although this often refers to a milder form of the illness.