Unnecessary testing for Lyme disease leads to inappropriate care. Antibiotic treatment rarely helps and poses risks of its own. (Victoria Arocho/Associated Press)

Diagnosing and treating Lyme disease isn’t as simple as you might think. In fact, experts are warning that many doctors don’t properly test for the infection and often don’t treat it right, either. ¶ The American College of Rheumatology, which represents specialists in Lyme and related diseases, recently warned that doctors often test for the disease unnecessarily. In some cases, that happens even when symptoms are so clear that treatment should start immediately. In other cases, it happens when doctors test patients who have only vague symptoms. That practice can lead to inappropriate treatment with antibiotics, exposing people to needless risk and speeding the spread of dangerous antibiotic-resistant bacteria. ¶ Other experts worry about the long-term use of antibiotics to treat lingering symptoms, an approach some doctors still take despite strong evidence that it rarely helps and poses even more risks. Here’s Consumer Reports’ advice on when you need testing and treatment for Lyme disease — and when you don’t.

Too many tests

Most people infected with Lyme develop the disease’s hallmark bull’s-eye rash — a painless red circle surrounding the bite — shortly after being infected. Yet people with the rash often test negative for Lyme because it can take up to a month for the body to produce enough antibodies to be detected by the Lyme disease blood test.

That’s why if you have the rash and were recently bitten or exposed to deer ticks, you don’t need to be tested but instead should be immediately prescribed antibiotics. Prompt treatment with two to three weeks of the drugs usually clears up the infection.

You also don’t need to be tested for Lyme if you have only vague symptoms, such as fatigue or mild aches and pains, with no history of a rash. In such cases, testing can lead to a misdiagnosis of Lyme disease because diseases such as rheumatoid arthritis, lupus and other autoimmune disorders produce antibodies that may be misinterpreted.

So when does testing make sense? You should be tested if you don’t have a rash but were definitely exposed to ticks and have other signs of Lyme disease. Those include acute flulike symptoms such as fever, severe muscle aches, joint pain with inflammation and headache. Other complications can include paralysis of one side of the face (similar to Bell’s palsy), or redness, warmth and swelling of a joint, usually a knee. Lyme disease can also slow your heart rate by causing a condition called heart block, although that’s less common.

Problems with antibiotics

Nearly 80 percent of people who are inappropriately tested, including those with vague symptoms of Lyme disease — or even no symptoms — are prescribed antibiotics regardless of their test results, according to the American College of Rheumatology.

That’s a problem for several reasons. First, antibiotics can cause side effects including allergic rashes, nausea, vomiting, prolonged diarrhea and, in rare cases, life-threatening reactions. Second, while antibiotics usually aren’t expensive, any money spent on unnecessary drugs is money wasted. And last, using antibiotics when you don’t need them fuels the growth of antibiotic-resistant bacteria, germs that can’t be easily treated with many currently available drugs. That threatens the public at large and it also threatens you if you become infected with drug-resistant bacteria.

Also problematic is when vague symptoms — such as fatigue, headache, joint pain without inflammation, lack of concentration and muscle aches — linger despite adequate antibiotic treatment.

Researchers acknowledge that joint pain and nerve symptoms sometimes last for a year or more, perhaps because of damage from inflammation or an autoimmune response. Anti-inflammatory drugs or medicine to rein in the immune system might help in such cases.

But some physicians treat vague, lingering symptoms with prolonged or repeated courses of antibiotics. That’s rarely appropriate, for several reasons.

First, research suggests that those symptoms may be no more common in people with Lyme disease than they are in people who never had it. In addition, a series of trials sponsored by the National Institutes of Health found that the long-term use of antibiotics did not relieve those persistent symptoms.

Finally, the treatment poses serious risks, including fatal blood infections stemming from the intravenous lines used to administer the drugs.

Copyright 2013. Consumers Union of United States Inc.

For further guidance, go to www.ConsumerReports.org/Health, where more detailed information, including CR’s ratings of prescription drugs, treatments, hospitals and healthy-living products, is available to subscribers.