Diagnosing strep throat

Diagnosing strep throat

Which medical professionals can examine and diagnose conditions associated with sore throats?

  • Family physicians or general practitioners (GP)
  • Paediatricians
  • Nurse practitioners
  • Physician assistants
  • ENTs (ear, nose and throat specialists) or otolaryngologists
  • Internists

What to do before a doctor’s appointment for a sore throat

If strep throat is suspected, a person can take precautions ahead of their initial doctor’s visit, so as to avoid potentially spreading infection to others. Precautions can include:

  • Practicing good hygiene: Being mindful of covering the nose and mouth if coughing or sneezing, not sharing personal care items (toothbrushes etc) and washing hands frequently.

The following can also be done to help alleviate symptoms and aid in recovery:

  • Gargling with a salt and warm water solution (do not swallow).
  • Taking care to rest, eat soft foodstuffs (where possible) and drink plenty of fluids.

How is strep throat diagnosed?

Once at the doctor’s office a discussion regarding symptoms, medical history and other relevant information will take place between the health professional and patient.

Some questions which a doctor may ask to assess for strep throat include:

  • How long ago did symptoms begin?
  • Have symptoms gotten better or worsened during the time between onset and the appointment?
  • Are symptoms mild in nature or intolerable (severe)?
  • To your knowledge, has anyone you known been diagnosed with strep throat? Have you been in their company recently (last several weeks)?
  • Have you, yourself ever been diagnosed with and treated for strep throat?
  • Do you have any other medical conditions?

From there a doctor will wish to conduct a physical examination and look for signs of inflammation in and around the throat area. He or she will assess the neck for swollen lymph nodes.

Strep throat may be strongly suspected if the following are evident during the consultation:

  • If you are aged between 5 and 15
  • If infection has taken place during the colder months of the year
  • If you have a high fever, swollen and enlarged lymph nodes
  • If you have redness and swelling in the throat
  • If you do have symptoms which are more associated with a bacterial infection rather than a viral one

There is no single diagnostic symptom for strep throat. A test should be done to officially diagnose the condition. In order to make a diagnosis or rule out any other conditions, a doctor may request tests. These may include:

  • Cotton swab stick for strep throat testing.A rapid strep test (rapid antigen detection test): This can be done during the appointment in the doctor’s office. A doctor will gently sweep a long cotton swab across the back of the throat to collect a sample for testing. This will then be packaged and sent to the laboratory for evaluation (i.e. to determine signs of bacteria or antigens). Results can be ready in a matter of minutes (10 to 15 minutes) or up to a few days.
  • A throat culture: Another sterilised cotton swab may be rubbed over the back of the throat to collect a secretion sample. This is then appropriately packaged for analysis in a laboratory where it will be cultured (combined with a substance that promotes bacterial growth). The results may take up to two days (24 to 48 hours) before the presence of bacteria can be determined or identified. The culture will be negative for bacteria if no growth takes place. A throat culture is the more accurate of the two tests and is required for diagnosis of strep throat.

Testing is not usually required in the following instances:

  • A person may have been exposed to strep causing bacteria but displays no symptoms. Testing will only be required when and if symptoms develop (thus making the individual contagious and ill). It is highly unusual to catch strep throat from a carrier (an asymptomatic individual).
  • Following completion of antibiotic treatment, unless symptoms have not cleared. If symptoms recur testing may be required to determine the cause and implement more appropriate treatment.

 Colony of bacteria in a culture medium plate or dish.

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