Scarlet fever has been a topic of conversation in recent months with spikes of the bacterial illness being seen. How much do you know about this historic illness? We spoke to Consultant Paediatrician, Dr Andrew Raffles to find out more about the disease and what treatment options are available.
What is Scarlet fever?
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 Strep A, 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. It is a common cause of infection in adults and children. The bacteria can be spread in droplets in the coughs or sneezes of someone with an infection, or through direct contact with an infected person or contaminated object.
What are the symptoms?
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.
Scarlet fever usually starts with a sudden fever associated with sore throat, swollen neck glands, headache, nausea, vomiting, loss of appetite, swollen and red strawberry tongue, abdominal pain, body aches, and general malaise. Scarlet fever usually follows a sore throat or a skin infection, such as impetigo, caused by particular strains of the streptococcus bacteria, but particularly Strep A. Initial symptoms usually include a sore throat, headache and a high temperature (38.3C/101F or above), flushed cheeks and a swollen and reddened tongue, sometimes called strawberry tongue.
A day or two later the characteristic pinkish or scarlet 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 characteristic rash appears 12–48 hours after the start of the fever. The rash usually starts below the ears, neck, chest, armpits and groin before spreading to the rest of the body over 24 hours.
Scarlet spots or blotches, giving a 'boiled lobster' appearance, are often the first sign of rash.
As skin lesions progress and become more widespread, they start to look like sunburn with goose pimples. The skin may have a rough sandpaper-like feel and it may be itchy. On darker skin the rash may be more difficult to see although its rough texture should be apparent.
In body folds, especially the armpits and elbows, fragile blood vessels (capillaries) can rupture and cause classic red streaks called Pastia lines. These may persist for 1-2 days after the generalised rash has gone.
In the untreated patient, the fever peaks by the second day and gradually returns to normal in 5–7 days. When treated with appropriate antibiotics, the fever usually resolves within 12-24 hours.
By about the sixth day of the infection the rash starts to fade and peeling, similar to that of sunburned skin, occurs. Peeling of the skin is most prominent in the armpits, groin, and tips of the fingers and/or toes and may continue up to 6 weeks.
How contagious is Scarlet fever?
Scarlet fever is very contagious and can be caught easily 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 healthy carriers – people who have the bacteria in their throat or on their skin but don't have any symptoms.
What treatment options are available?
Scarlet fever used to be a very serious illness, as it can in some cases cause damage to heart valves, as well as triggering a reaction in the kidney called glomerulonephritis. 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.
Are there any long term side effects of the bacteria called Strep A?
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 rheumatic fever – and affecting the heart and kidneys.
How long is recovery?
The fever usually subsides within a few days, and recovery is complete by two weeks. Recovery is usually uncomplicated and can be very fast with antibiotics. Of note is the strain of bacteria that causes scarlet fever has become weaker with time, and seems to cause fewer side effects, although the numbers of cases have increased in the last 2-3 years.
Should I be concerned about other children/ family members in the house catching it?
Scarlet fever is not as common as it was a century ago when it was associated with deadly epidemics. The development of antibiotics and their early use in the treatment of streptococcal infections has prevented many cases of scarlet fever and the long-term complication of rheumatic fever.
Scarlet fever occurs mostly in children aged 4-8 years. By 10 years old, up to 80% of children have developed lifelong protective antibodies against streptococcal toxins, whilst children younger than 2 years still have acquired maternal antiexotoxin antibodies. Males and females are affected equally.
Those at greatest risk for scarlet fever include:
- People living in overcrowded environment such as boarding schools, day care or military camps
- Children older than 3 years
- People in close contact with someone who has a strep throat or skin infection
- Children recovering from Chickenpox, and with long standing eczema
How can I avoid my children getting it?
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.