Streptococcal A infection, invasive strep A and scarlet fever – what to look out for and what to do
What is a Streptococcal infection?
These infections are caused by several strains of bacteria – the most common are streptococcus A and streptococcus B. These infections are extremely common and frequently responsible for sore throats experienced by millions of us every year.
Most group A streptococcal bacteria cause relatively mild skin and throat infections, and are responsible for common conditions such as:
- strep throat (sore throat)
- impetigo (localised infection of the skin producing pus-filled blisters)
- cellulitis (infection of the skin, fat and underlying tissues)
- erysipelas (inflammation of the upper layers of the skin)
- tonsillitis (severe throat infection particularly impacting the tonsils)
- scarlet fever (infection causing sore throat, fever and rash)
These infections are common and usually resolve quickly with antibiotics. It is rare for these infections to cause serious illness. If you or your child present with one of these infections contact your GP and get treatment early. It is not necessary to go to A&E.
Invasive streptococcal infection
However, Group A streptococcal bacteria can get into the blood, deep muscle or fat tissue and cause what are known as invasive streptococcal infections. These can be extremely serious and life threatening and are responsible for some of the following conditions:
- bacteraemia (blood infection) – which can lead to Sepsis
- endocarditis (heart lining infection)
- meningitis (brain and spinal cord inflammation)
- peritonitis (intestinal inflammation)
- urinary tract infection
- necrotising fasciitis (death of tissue under the skin which usually requires surgery)
- streptococcal toxic shock syndrome (infection causing low blood pressure and injury to organs such as the kidneys, liver and lungs – similar to Sepsis)
Some people are natural carriers of streptococcal bacteria on their skin or in their throat, vagina,
bladder or rectum. However, carriers do not usually develop an infection from this.
How is it passed on?
Streptococcal bacteria are spread by person-to-person contact with someone with an infection or less likely a carrier.
Streptococcal bacteria can also spread in droplets from the nose or throat of someone with an infection.
More rarely, streptococcal bacteria can enter the body in food contaminated with the bacteria – usually milk and milk products, and eggs.
Invasive streptococcal infections develop when bacteria gets past the body’s natural defences such as a break in the skin. Health conditions that reduce immunity to infection
make invasive infections more likely, so people with chronic illnesses like cancer, diabetesand kidney disease, and those who use medications such as steroids, are at greater risk. However invasive streptococcal infections can be a complication of other streptococcal conditions such as Scarlet Fever and so parents should be vigilant for early signs that their child may be getting worse or becoming seriously ill.
Preventing the spread of Streptococcus
The spread of bacteria can be reduced by good hand washing, especially after coughing and sneezing, before preparing foods and before eating.
Cuts, grazes and other wounds should be kept clean and watched for signs of infection, including swelling, redness, pus and pain in the area of the wound. If you see any of these signs, you should visit your GP.
What will the doctor do?
Streptococcal infections are diagnosed by testing a swab from the throat, or by a blood or urine test. In all three cases, the test checks for the presence of streptococcal bacteria.
Infections are treated with antibiotics.
Invasive streptococcal infections usually require intravenous antibiotics given directly into a vein. The patient will need to be admitted to hospital and may require intensive care.
Invasive infections that affect soft tissue, bone or muscle may require surgery. Early treatment improves the outlook greatly, but some invasive streptococcal infections and some group B streptococcal infections can be fatal.
All strains of streptococcal bacteria can cause complications such as rheumatic fever (infection affecting the heart and joints) and glomerulonephritis (kidney inflammation).
Sometimes Public Health will advise that all close contacts of people with streptococcal infection are given antibiotics.
Streptococus A infection is also responsible for Scarlet Fever and there has been a recent surge in cases of this infection post pandemic.
Recognising if your child might have a streptococcal infection
There are lots of viruses that cause sore throats, colds and coughs circulating. These should resolve without medical intervention. However, children can on occasion develop a bacterial infection on top of a virus and that can make them more unwell.
As a parent, if you feel that your child seems seriously unwell, you should trust your own judgement.
Contact NHS 111 or your GP if:
- your child is getting worse
- your child is feeding or eating much less than normal
- your child is not drinking and not passing much urine
- your baby is under 3 months and has a temperature of 38°C, or is older than 3 months and has a temperature of 39°C or higher
- your baby feels hotter than usual when you touch their back or chest, or feels sweaty
- your child is very tired or irritable
Call 999 or go to A&E if:
- your child is having difficulty breathing – you may notice grunting noises or their tummy sucking under their ribs
- there are pauses when your child breathes
- your child’s skin, tongue or lips are blue
- your child is floppy and will not wake up or stay awake
- Your child isn’t drinking and hasn’t had a wee or a wet nappy in the last 12 hours
- They have mottled skin and their limbs are abnormally cold
What are the symptoms?
Streptococcal bacteria cause a wide range of infections. Each infection produces different symptoms.
Symptoms of the most common streptococcal infection – strep throat – include:
- sore, red throat
- fever, headache
- swollen lymph nodes (lumps) in the neck and under the jaw
Good hand and respiratory hygiene are important for stopping the spread of many bugs. By teaching your child how to wash their hands properly with soap for 20 seconds, using a tissue to catch coughs and sneezes, and keeping away from others when feeling unwell, they will be able to reduce the risk of picking up or spreading infections.
Scarlet fever is a contagious infection that mostly affects young children.
It’s easily treated with antibiotics and most people make a relatively swift and full recovery. If you think you or your child might have it, you should see your GP and not visit A&E
Recognising the signs scarlet fever:
The first signs of scarlet fever can be flu-like symptoms, including a high temperature, a sore throat and swollen neck glands (a large lump on the side of your neck).
A rash appears 12 to 48 hours later. It looks like small, raised bumps and starts on the chest and tummy, then spreads. The rash makes your skin feel rough, like sandpaper.
Scarlet fever rash on white skin the rash looks pink, red or purple. It may be harder to see on darker skin, but you can still feel it.
A white coating also appears on the tongue. This peels, leaving the tongue red, swollen and covered in little bumps (called “strawberry tongue”).
The rash does not appear on the face, but the cheeks can look red. The redness may be harder to see on brown and black skin.
The symptoms are the same for children and adults, although scarlet fever is less common in adults.
See a GP if you or your child:
- have scarlet fever symptoms
- do not get better in a week (after seeing a GP)
- have scarlet fever and chickenpox at the same time
- are ill again, weeks after scarlet fever got better – this can be a sign of a complication, such as rheumatic fever
- are feeling unwell and have been in contact with someone who has scarlet fever
- Scarlet fever is highly contagious. Check with a GP before you go in. They may suggest a phone consultation. Early treatment of scarlet fever with antibiotics is important to reduce the risk of complications such as pneumonia or an invasive infection.
If your child has scarlet fever, keep them at home until at least 24 hours after the start of antibiotic treatment to avoid spreading the infection to others.
What happens at your appointment
GPs can often diagnose scarlet fever by looking at your tongue and rash.
Sometimes they may:
- wipe a cotton bud around the back of your throat to test for bacteria
- arrange a blood test or take a urine sample
All these tests are looking for the presence of a streptococcal infection.
Treating scarlet fever
A GP will prescribe antibiotics. These will:
- help you get better quicker
- reduce the chance of a serious illnesses
- make it less likely that you’ll pass the infection on to someone else
Keep taking the antibiotics until they’re finished, even if you feel better.
Things you can do yourself: You can relieve symptoms of scarlet fever by:
- drinking cool fluids
- eating soft foods if you have a sore throattaking painkillers like paracetamol to make you feel better and these will also help bring down a high temperature (do not give aspirin to children under 16)
- using calamine lotion or antihistamine tablets to ease itching
How long does scarlet fever last? Scarlet fever lasts for around 1 week.
You can spread scarlet fever to other people up to 6 days before you get symptoms until 24 hours after you take your 1st dose of antibiotics.
If you do not take antibiotics, you can spread the infection for 2 to 3 weeks after your symptoms start.
Important: If you or your child has scarlet fever, stay away from nursery, school or work for 24 hours after you take the 1st dose of antibiotics.
Is scarlet fever dangerous?
Scarlet fever can be a serious illness. However most cases will respond quickly to antibiotics and your child will feel unwell and then recover within a week. There is a recent increase in cases.This is probably due to children having been less exposed to streptococcus and other infections during lockdown.
Scarlet Fever is a notifiable disease in the UK – this means that health professionals must inform Public Health if they suspect someone has it.
Complications from scarlet fever itself are rare. They can happen during or in the weeks after the infection. However, it is possible that the infection develops into an invasive infection that can be life threatening.
- ear infection
- throat abscess
- rheumatic fever
- Invasive streptococcal infection that will need hospital treatment and can be very serious.
There’s no evidence to suggest that getting scarlet fever during pregnancy will harm your baby.
But it can make you feel unwell, so it’s best to avoid close contact with anyone who has it.
Contact a GP if you get symptoms.
Many of the antibiotics used for scarlet fever are considered to be safe to take during pregnancy.
How to avoid spreading scarlet fever
Scarlet fever is very infectious and can easily spread to other people.
To reduce the chance of spreading scarlet fever:
- wash your hands often with soap and water
- use tissues to trap germs from coughs or sneezes
- bin used tissues as quickly as possible
Don’t: share cutlery, cups, towels, clothes, bedding or baths with anyone who has symptoms of scarlet fever
Information compiled from NHS and Government resources.
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