The only way to know for sure if your sore throat is strep is to have a rapid strep test or a throat culture. These tests must be performed at a physician's office, but let's face it you can't go running in to the doctor every time your throat gets a little scratchy.
Characteristics of strep throat include a severe sore throat that may cause pain or difficulty swallowing. The back of the throat is usually very red and there may be white patches in the back of the throat or on the tonsils. The tonsils and lymph nodes also may be swollen. Some people get a fever. It is not uncommon to be very tired and achy or to lose your appetite. In some cases you may get a rash.
The biggest difference between strep throat and a cold virus is that strep throat usually does not cause runny nose, congestion, sneezing or coughing.
All cases of strep throat must be treated with an antibiotic to avoid serious complications including heart problems, kidney problems or Scarlett fever -- especially in children. For these reasons, it is very important to see the doctor if you or your child have symptoms of strep throat.
Medline Plus. Strep Throat. Accessed: October 2, 2009 from http://www.nlm.nih.gov/medlineplus/ency/article/000639.htm