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.
Scarlet fever symptoms
Scarlet fever usually follows a sore throat or a skin infection, like impetigo, caused by particular strains of Streptococcus bacteria.
The symptoms of scarlet fever usually develop 2 to 5 days after infection. However, the incubation period (the period between exposure to the infection and symptoms appearing) can be as short as one day or as long as 7 days.
The distinctive pink-red rash caused by scarlet fever develops 12 to 48 hours after symptoms like a sore throat or headache.
Red blotches are the first sign of the rash. These turn into a fine pink-red rash that feels like sandpaper to touch and looks like sunburn. It may also be itchy.
On darker skin the rash may be more difficult to see although its rough texture should be apparent.
The rash usually starts on the chest and stomach, but soon spreads to other parts of the body, like the:
- inner thighs
The rash doesn't usually spread to the face. However, the cheeks become flushed and the area just around the mouth stays quite pale. The rash will turn white if you press a glass on it.
The rash usually fades after about a week, but the outer layers of skin, usually on the hands and feet, may peel for several weeks afterwards.
In milder cases, sometimes called scarlatina, the rash may be the only symptom.
Other symptoms of scarlet fever
Other symptoms of scarlet fever may include:
- swollen neck glands
- loss of appetite
- nausea or vomiting
- red lines in the folds of the body, such as the armpit, which may last a couple of days after the rash has gone
- a white coating on the tongue, which peels a few days later leaving the tongue red and swollen (this is known as strawberry tongue)
- a general feeling of being unwell
When to seek medical advice
If you think you or your child may have scarlet fever, see your GP for a proper diagnosis and appropriate treatment. It usually clears up after about a week
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 infectious 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 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 of scarlet fever occur in children under 10 (usually between 2 and 8 years of age). However, people of any age can get the illness.
As it's easily spread, 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 can 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 have scarlet fever more than once, but this is rare.
Treating scarlet fever
Most cases of scarlet fever clear up after about a week without treatment. However, your GP may recommend treatment as it:
- reduces the length of time you're infectious
- speeds up recovery
- lowers the risk of complications of scarlet fever
With treatment, most people recover in about 4 to 5 days and can return to nursery, school or work 24 hours after starting antibiotic treatment.
Without treatment, you'll be infectious for 1 to 2 weeks after symptoms appear.
Scarlet fever is usually treated with a 10-day course of antibiotics. This is often in the form of penicillin or amoxicillin tablets, although liquid may be used for young children.
For people who are allergic to penicillin, alternative antibiotics like erythromycin can be used instead.
The symptoms usually improve within 24 hours of starting antibiotics, with the other symptoms disappearing within a few days. However, it's important that the whole course of treatment is completed to ensure the infection is fully cleared and reduce the potential for antibiotic resistance.