Tonsillitis in Children: Is It Strep? Do Antibiotics Help?
Most cases of tonsillitis in children are caused by viruses, even when there is a high fever and white spots on the tonsils. We explain which clues point to strep, how a rapid test confirms it, and what antibiotics are really for.
Virus or Bacteria: What Causes Tonsillitis in Children
Most cases of tonsillitis in children are viral. Group A streptococcus, Streptococcus pyogenes, causes two to three in every ten cases in children aged five to fifteen. It is rare in children under three.
White patches don't help tell them apart. The mononucleosis virus and adenovirus can also cover the tonsils in pus. So pus in the throat doesn't mean a bacterial infection.
Signs That Point to a Virus
A virus usually gives itself away through the symptoms that come with it: a cough, runny nose, hoarseness, red eyes, mouth sores or diarrhoea. Strep almost never causes a cough.
Four Clues That Suggest Strep
The first is a high fever that comes on suddenly, often with a headache. The second is swollen glands under the jaw that hurt at the slightest touch.
The third can be seen with a torch: tiny red dots sometimes appear on the roof of the mouth. These are petechiae, minute spots of blood under the lining of the mouth.
The fourth is the one that causes the most confusion at home: tummy ache and vomiting. Some children complain more about their stomach than their throat.
Even so, with all four clues present, a diagnosis based on appearance alone is right only about half the time.
The Rapid Test: Results in About Ten Minutes
A swab is rubbed over both tonsils and the back of the throat. A reagent looks for an antigen, a component of the bacterium's cell wall. The result is ready in about ten minutes.
A positive result is almost certain. A negative result is less reliable: it misses one to two infections in every ten. If suspicion is high, the paediatrician may order a throat culture.
The test isn't done on every child. Some healthy children carry strep in their throat without it causing any problems. If one of them has a cold with a cough and runny nose and tests positive, antibiotics won't help.
What Antibiotics Are Really For
With antibiotics, a sore throat clears up only about a day sooner. Without them, symptoms usually ease within three to five days.
The reason for treatment is what can happen around three weeks later. The immune system produces antibodies against the bacterium's M protein. This protein resembles molecules found in the heart, joints and brain.
Sometimes those antibodies attack the body itself. This is rheumatic fever, which can cause lifelong damage to the heart valves. It is rare in Spain. Worldwide, rheumatic heart disease affects tens of millions of people, especially where these infections go untreated.
The usual treatment is penicillin or amoxicillin for ten days, even if the child feels well by the third day. Treatment still protects even if it is started up to about nine days after symptoms begin. After twenty-four hours, the child is no longer contagious.
When to Go to A&E
Go to A&E if your child is drooling because they can't swallow their saliva, is having trouble breathing, can barely open their mouth, or has one side of the neck that is very swollen.
Frequently asked questions
Do white spots on the tonsils mean it's a bacterial infection?
No. Viruses such as the mononucleosis virus or adenovirus can also cover the tonsils in pus.
Is the rapid strep test reliable?
A positive result is almost certain. A negative result misses one to two infections in every ten, so the paediatrician may order a throat culture if suspicion is high.
Why does my child need to take antibiotics for ten days if they already feel better?
Because the main goal is to prevent rheumatic fever, which can develop around three weeks later and damage the heart valves.
When does a child with strep tonsillitis stop being contagious?
Twenty-four hours after starting antibiotics.
Informative article written with the help of AI tools from the verified script of the video. The video is in Spanish.