Streptococcal Infection ( Sore throat with/without Scarlet Fever )

What is strep throat?

Virtually all bacterial sore throats are caused by streptococcal bacteria (more commonly known as “strep”). The incubation period is between 2-5 days. The main symptom is a sore throat, but other symptoms may include a fever, headache, stomachache and vomiting. The tongue may become red with white spots like a strawberry. Often it just remains an upper respiratory tract infection, i.e. a common cold. However, if a rash appears, then it is called “scarlet fever”. The rash first appears on the neck and chest and then covers the entire body within 24 hours.


It’s not possible to make a definite diagnosis of strep throat from a viral sore throat on the basis of symptoms alone.
The only method is through a throat test (rapid strep) or throat culture. We usually use “rapid strep”.


A 10 day course of antibiotics (usually penicillin) is prescribed to clear the infection as well as to prevent any complications such as acute nephritis or more rarely rheumatic fever. (When the child is allergic to penicillin, erythromycin will be prescribed instead.)
Cold liquids and Tylenol/Paracetamol or Ibuprofen are effective for reducing the pain and fever. To make sure there are no complications we recommend that you bring your child back for a urine test after 3 weeks.

Possible Complications

Acute nephritis: This is inflammation of the kidneys. It will appear about 3 weeks after the initial infection. Since it cannot be prevented by antibiotics we strongly recommend that you bring your child back for a urine test.

Rheumatic fever: This causes painful swollen joints, unusual skin rashes and heart damage in half of its victims. It can be prevented with antibiotics.

When treating your child at home

1 Other family members:
The patient is contagious for 5-6 days starting from the day before the fever first occurred. It is possible that other family members may be infected. However, within 24 hrs of starting the antibiotics, the patient is no longer contagious. We do not usually give prophylactic antibiotics to the whole family. Please make an appointment with the doctor if other family members should develop symptoms such as a sore throat.

2 Food: No restrictions
However, try to avoid hot, spicy or sour foods as they may worsen the pain.

3 Bathing : No restriction as long as the child doesn’t have a fever.

4 School/Nursery: The child may go to school 24 hours after starting antibiotics, since s/he will no longer be contagious.

When to seek further medical attention

When your child’s fever hasn’t gone down, 48 hours after starting the course of antibiotics.
When your child’s throat is so swollen s/he is unable to take fluids.

Urine Test

To make sure your child’s kidneys are okay, please hand in a urine sample around 3 weeks after the infection. If possible, have your child give the sample just after getting out of bed in the morning

Keiko Fukuyama M.D.