Answer:

Tammy has lots of good company with her type of symptoms. It's amazing how often someone will reach for a bottle of old antibiotics, or borrow from a friend, in hopes of catching an infection early. How helpful is this, and what problems might result?

With a sore throat, runny nose, and fever, Tammy might have any one of a number of viral respiratory infections. There is also a chance she has a strep throat. As most people know, antibiotics will do nothing for a viral infection. And inappropriate use will just increase the problem of antibiotic-resistant bacteria in the body. So, now she's screwed things up. A throat culture can't be done because her antibiotics will have suppressed any strep that might be present. We will have to guess whether or not she has strep.

How can a person tell if they have a strep throat? Well, usually they can't. The odds of having strep are higher if you have a combination of white spots on the tonsils or back of the throat, enlarged lymph glands in the neck, and a fever. Even with all those signs, there is still only about a 50:50 chance of strep. With two or less of these signs, the chance of strep is even lower. With these sorts of odds it becomes clearer why throat cultures are desirable. The rest of an examination will help make sure Tammy has not developed an ear infection, pneumonia, or other complication.

In this case, I would stop her antibiotics (the amoxicillin is probably causing her diarrhea anyway) and do the usual cold remedy stuff using Tylenol, rest, fluids, herbal teas, decongestants, and so forth. Happily, most people who responded to the Puzzler recommended the same thing. We'll just have to take the chance that a strep throat is being overlooked. Of course, even if she had strep, it will get better on its own anyway. The main reason for treating strep is to prevent previously common complications such as rheumatic fever or tonsillar abscesses.