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Post Category: iGAS and Scarlet Fever

A WonderCare Guide to Invasive Group A Streptococci (iGAS)

A WonderCare Guide to Invasive Group A Streptococci (iGAS)

What is Group A Streptococci (GAS)?

GAS is a bacteria which lives on peoples skin and in their throat.  Usually this doesn’t cause any problems and people won’t even know it’s there!  However, Sometimes it does cause illness in the form of Scarlet Fever, a sore throat (strep throat) or even Impetigo.

What is Invasive Group A Streptococci (iGAS)?

Very rarely the GAS bacteria journeys into the blood or spinal fluid.  This very serious infection is known as Invasive Group A Streptococci or iGAS.  iGas can result in  streptococcal toxic shock syndrome or necrotising fasciitis.  These are extremely serious conditions.

In Ireland, GAS is not a notifiable disease, however iGAS is.  This means that all medical practitioners are required to notify the Medical Officer of Health(MOH)/Director of Public Health (DPH) of when iGAS is detected.  This information is used to investigate cases thus preventing spread of infection and help to identify potential outbreaks.

Symptoms of iGAS

  • A high fever.
  • Severe muscle aches.
  • Redness or blisters at the site of a wound.
  • Localised muscle tenderness (so tenderness in one area of muscle).
  • Low blood pressure and dizziness.
  • Confusion.
  • Nausea and Vomiting.
  • Stomach Pain

Whilst iGAS does not always begin as a result of Scarlet Fever, due to their common origin from Group A Streptococci, it is clear that the risk of iGAS is higher when levels of Scarlet fever circulating are higher.

It is important so to highlight the symptoms of Scarlet Fever so that parents can be alert for the rare but possible development of iGAS.

Scarlet Fever

It most commonly affects children between the ages of four and ten and often affects people who have been in contact with someone with a streptococcal throat or skin infection.  Children under two have some immunity from their mothers and children over ten will have developed immunity themselves to the toxins from streptoccal bacteria.


A child can start to show symptoms of scarlet fever within one to seven days of exposure.

  • Rash – Your child will often suffer from the other symptoms of scarlet fever as described below for a day or two before the rash appears. The rash generally starts with red blotches which develops into the characteristic pink-red rash which feels like sandpaper. It is often referred to as looking like sunburn.  It most commonly starts on the torso and spreads to other areas like the legs, arms and groin areas.  The face is generally not affected by the rash itself but does tend to become flushed which can be a distinguishing feature.  The rash tends to last around one week and like some other skin infections it can cause peeling of the skin on the hands and feet for a scarletfevertonguefew weeks after.
  • High temperature
  • Sore throat
  • Headache
  • Swollen tongue –  Can be red and tender or  thick (swollen) with a white coating which may peel.
  • Nausea/vomiting/loss of appetite
  • Swollen neck glands


doctor-logo-red-white-mdIf you suspect scarlet fever see your GP.  They will most likely prescribe a ten day course of an antibiotic called penicillin (or an alternative if your child has an allergy).  Using an antibiotic is important in scarlet fever to speed up your child’s recovery but also to reduce the length of time that they remain contagious.  If they take the antibiotic they will be able to return to childcare after 24 hours but if they do not receive an antibiotic they will remain contagious for one to two weeks after they first developed symptoms.  So whilst it is a rare illness in Ireland now and most cases are mild it is still important to seek medical attention if you suspect your child may have Scarlet Fever. Your child may appear better within a day or two of starting treatment but as with all infections it is important to finish the course of antibiotics.  If scarlet fever is untreated there is the risk of developing complications such as a throat abscess, ear infection, or pneumonia.

  • Fever should be treated as you normally would – you can read more about that here.
  • You can also listen to my fighting fever episode on A WonderCare Podcast here!
  • Provide frequent fluids, little and often if necessary and watch out for signs of dehydration such as dry nappy for more than 12 hours, a sunken fontanelle, or drowsiness.  Ensure to see the doctor if your child has taken less than 50% of their normal fluids in the last 24hours.
  • Provide soft foods for sore throats.  Things like cold yoghurts, ice pops or even warm soup can all help to ease the pain of swallowing and help to prevent dehydration.


Risk of iGAS

Very rarely untreated scarlet fever can result in complications such as blood poisoning, toxic shock syndrome and damage to the kidneys.  It is important to seek medical attention if your child’s condition is not improving with treatment of antibiotics.


I hope you have found this article helpful and if you have any questions at all please don’t hesitate to contact me by sending a private message to the WonderCare facebook page or Instagram or my website contact page .


Author: WonderCare Blog

My name is Sheena Mitchell, I'm a pharmacist with my own business Milltown totalhealth Pharmacy in Dublin 6. From working in the pharmacy I've realised that there are a lot of first time and experienced parents who might benefit from hints and tips from a pharmacist who can balance healthcare advice with real hands on experience from my important work as a mother of three! I hope to bring you regular advice and information and answer questions that you have! Being a mother and pharmacist are my two favorite things and I'm delighted to have this way of bringing my two worlds together! All questions and queries are gratefully received but otherwise sit back, relax, and let the solutions come to you! Check out A WonderCare Podcast!