Group A streptococcus (GAS) is a common type of bacteria. Many people carry it in their throat or on their skin without becoming ill. However, it can sometimes cause infections, ranging from mild illnesses to more serious conditions.

GAS can affect the skin, soft tissues and respiratory system. It can cause a range of infections, including tonsillitis, pharyngitis (sore throat), scarlet fever, impetigo and cellulitis, among other infections.

Although infections caused by GAS can be unpleasant, they are usually mild and rarely lead to serious illness. Most people with conditions such as tonsillitis are no longer contagious around 24 hours after starting antibiotic treatment.

Scarlet fever is a common illness associated with GAS. Early symptoms can feel similar to flu and may include a high temperature, sore throat, and swollen glands in the neck.

A distinctive rash usually develops 12 to 48 hours later. It often starts on the chest and tummy before spreading to other parts of the body. The rash appears as small, raised bumps and gives the skin a rough, sandpaper-like texture. On darker skin tones, the rash may be harder to see but will still feel rough to the touch.

Visit the NHS website to learn about the signs and symptoms of scarlet fever, including photographs of the rash

What is invasive group A streptococcus (iGAS)?

The most serious infections linked to GAS are known as iGAS.

iGAS occurs when the bacteria enter parts of the body where they are not normally found, such as the bloodstream, lungs, or deep tissues. This can happen through cuts, sores, or wounds, or when the body's natural defences are weakened following a viral infection such as flu or chickenpox.

People with weakened immune systems are at greater risk of developing invasive disease. Children who have recently had chickenpox or flu may also be more vulnerable to serious infection.

Although iGAS infections are rare, they can be very serious and, in some cases, life-threatening.

Early treatment with antibiotics is important. If you are concerned that you or your child may have symptoms of a GAS infection, seek medical advice as soon as possible.

What should parents and carers do?

  • Be aware of the signs and symptoms of GAS and scarlet fever. If you or your child develops symptoms, seek advice from your GP or call NHS 111.

  • Make sure your child completes the full course of any antibiotics prescribed, even if they start to feel better.

  • Keep your child away from nursery, school or other activities until they have been taking antibiotics for at least 24 hours. For impetigo, they should stay at home for 48 hours after starting treatment.

  • Children who have recently had chickenpox or flu may be at a higher risk of developing a more serious infection. Seek medical advice promptly if your child has a persistent high temperature, a skin infection (cellulitis), joint pain or swelling, or if you are otherwise concerned about their condition.

  • If your child has a condition that affects their immune system, speak to your GP or hospital specialist to find out whether any additional precautions are needed.

  • Encourage good hand hygiene by washing hands regularly with soap and warm water for at least 20 seconds. Teach children to catch coughs and sneezes in a tissue and dispose of it straight away. Keeping unwell children at home can also help prevent the spread of infection.

  • Clean and cover any cuts, grazes, sores or insect bites to reduce the risk of infection.

  • Keep your child's school or nursery informed if they have been diagnosed with GAS, scarlet fever or another related infection.

If your child seems seriously unwell

Trust your instincts. You know your child best.

Contact your GP or NHS 111 if:

  • your child’s condition is getting worse

  • your child is drinking, feeding, or eating much less than usual

  • your child has not had a wet nappy for 12 hours or more, or shows other signs of dehydration, visit the NHS website for guidance on dehydration

  • your baby is under three months old and has a temperature of 38°C or above

  • your child is three months or older and has a temperature of 39°C or above

  • your baby feels unusually hot to the touch on their chest or back, or is sweating more than usual

  • your child is very tired, difficult to wake, or unusually irritable.

Call 999 or go to A&E immediately if:

  • your child is struggling to breathe, making grunting noises, or their tummy is pulling in under their ribs when they breathe

  • your child has pauses in their breathing

  • your child’s skin, lips, or tongue turn blue or grey, visit the NHS website for more information about blue or grey skin

  • your child becomes floppy, unresponsive, or cannot be woken up.