Viruses cause most sore throats, and there is no medicine, especially not antibiotics, that will cure them. (ISTOCKPHOTO)

“You mean you’re not going to prescribe an antibiotic?” The disappointed patient was a 50-year-old stockbroker who had come to see Consumer Reports’ chief medical adviser, Marvin M. Lipman, with a four-day history of sore throat, coughing, postnasal drip and low-grade fever. He said that his previous physician had always given him a Z-Pak (a five-day course of the antibiotic azithromycin) for similar symptoms and that he always got better.

Lipman explained that it was more likely that he had a viral infection, for which an antibiotic would be useless, and he outlined some over-the-counter measures that might help. But the patient left the office in a huff, and Lipman never saw him again.

Too much of a good thing

The age of antibiotics began in the 1930s with the introduction of sulfa drugs, followed by penicillin in 1941. Since then, antibiotics have saved the lives of countless millions infected with deadly bacteria.

The war against viruses, with a few notable exceptions, has not been as successful. Nonetheless, physicians began writing antibiotic prescriptions for many viral infections “just in case” bacteria might also be involved. Patients including that stockbroker came to expect and even demand such treatment.

That’s not good medicine. Unnecessary antibiotics not only expose patients to such harmful side effects as debilitating diarrhea, but they also lead directly to the emergence of resistant strains of bacteria that go on to infect others.

In hospitals, about 50 percent of antibiotic use is either unnecessary or inappropriate, according to the Centers for Disease Control and Prevention. In doctors’ offices, where no one is keeping close track, the percentage may be even higher.

Nowhere is this more evident than in the treatment of sore throats, one of the most common reasons adults and children visit a doctor.

Even though it has been shown that a vast majority of sore throats are due to respiratory viruses such as adenovirus, respiratory syncytial virus and rhinovirus, they are often treated with antibiotics.

Physicians probably overuse antibiotics for viral sore throats in part to appease miserable patients desperate for a quick cure.

But the practice also dates to a time when untreated sore throats were occasionally followed by rheumatic fever or acute kidney disease. Those complications developed from infections caused by the group A beta-hemolytic streptococcus, or strep throat, which accounts for only 5 to 15 percent of all sore throats. The only other sore throat that can mimic strep throat (but with a negative throat culture) is the one that occurs with infectious mononucleosis.

Virus or strep?

Today, there is no need to give antibiotics “just in case” it’s strep. The organism can be reliably detected with a simple throat swab, with results available within 24 hours.

But the disease can almost always be distinguished from a viral sore throat on clinical grounds alone.

With strep, the patient is usually younger than 50 years of age, and the sore throat comes on like gangbusters within hours or overnight, making swallowing so difficult that drooling can occur. The breath has a foul odor, and even speech is affected. A fever in excess of 101 degrees, accompanied by chilly sensations, is common, and you can easily feel tender, swollen lymph nodes under the jaw. Inspection of the throat shows yellowish pus overlying the tonsils.

Since group A strep evidently lacks the ingenuity to have developed resistance, penicillin is still the mainstay of treatment unless you’re allergic to it.

Viral sore throats develop over the course of a few days and are invariably accompanied by a runny nose, postnasal drip, a cough with clear or greenish sputum, and a low-grade fever or no fever at all.

No medicine will cure them. The only treatment is “tincture of time” — waiting out the one to two weeks it can take for symptoms to abate on their own.

The flu (also a viral illness) has symptoms similar to a viral sore throat, except for more intense muscle aches and perhaps a higher fever, and is treatable with the antiviral drug oseltamivir (Tamiflu) if given early enough in the course of the illness.

You can manage symptoms with acetaminophen (Tylenol and generics), nasal sprays or drops, throat lozenges and gargling with warm saltwater.

Of course, there’s always good old chicken soup, which, in Lipman’s opinion, would have helped that stockbroker more than a whole carload of Z-Paks.

Copyright 2013. Consumers Union of United States Inc.