Lyme disease

Most cases are easy to diagnose and treat

The number of reported cases of Lyme disease in the United States has more than doubled over the last decade as a result of increased public knowledge and more accurate diagnostic capabilities. And as the weather heats up and families head to the woods of Connecticut or the beaches of Cape Cod for summer vacations, the incidence of the disease is likely to reach new heights this summer.

Despite the prevalence of Lyme disease, controversy continues over how best to diagnose and treat the illness. Ken McIntosh, MD, director of Children's Hospital Boston's Clinical Research Program, regularly talks to providers and patients about Lyme disease. "There's so much information out there on Lyme disease, especially on the Internet, that people can get confused about it," he says. "But most cases are quite straightforward, and easy to diagnose and treat."

Lyme disease is a spirochetal infection caused by a tiny, black tick often found on white-footed mice and white-tailed deer prevalent in woods and high grass. The disease attacks many of the body's organ systems, including the skin, heart, nervous system and joints. Three to 30 days after being bitten by a tick, patients present with a characteristic rash consisting of one or more round or oval pink spots, often accompanied by nonspecific symptoms such as headache, lymphad-enopathy, muscle or joint pains, and fatigue.

Posing an additional challenge, lab tests are usually ineffective as diagnostic tools early in the disease. But by examining the rash (which is often pink or red on the outside and clear in the middle, like a bull's eye), considering all the physical symptoms, and determining if there is either a history of a tick bite or exposure to areas where ticks are prevalent, Dr. McIntosh says the disease is relatively easy to spot. Treatment should begin immediately.

"Since lab tests are generally unhelpful at this stage," he says, "clinicians should proceed with two to three weeks of antibiotics such as amoxicillin or doxycycline, based solely on clinical findings." Although antibiotic treatment early in the disease is almost always effective, problems occur when patients don't go to the doctor's office until later in the disease, or in the rare instances when they don't respond completely to treatment. "If you keep it always in mind, later stage Lyme is still relatively easy to recognize," says Dr. McIntosh, "and the lab tests are very helpful at this point in the disease."

Symptoms of Stage II Lyme, which occurs weeks to months after a tick bite, include arthritis, multiple bull's eye rashes, and neurologic syndromes like lymphocytic meningitis and facial nerve palsies. By the time the disease reaches this stage lab testing is helpful with diagnosis, and Dr. McIntosh suggests sending specimens to a reputable lab for serologic testing. The first phase of this process is either an enzyme-linked immunosorbent assay (ELISA) or indirect fluorescent antibody (IFA) test, followed by a Western immunoblot (WB) test to verify the findings.

Once the diagnosis has been confirmed, clinicians should begin three weeks of treatment with antibiotics such as penicillin or ceftriaxone. As in Stage I, this treatment is almost always effective. In Stage III, Lyme disease in children is characterized by arthritis in the major joints. Adults with Stage III Lyme disease may show memory loss, mood changes and sleep disturbances, but these are very uncommon in children. Arthritis can occur weeks or even years after the initial infection, and oral antibiotic treatment with the above medications is recommended for 30 days. If this level of treatment proves ineffective, it may be helpful to administer a course of intravenous antibiotics.

Despite the fact that the disease occurs more often in children than adults, Dr. McIntosh has rarely, if ever, seen a child with the neurologic symptoms of late-stage Lyme. "People get very worried about the disease because troublesome symptoms like memory loss and dizziness are attributed to it more often than they should be," he says. "But the fact remains that if you catch and treat the disease early, you'll achieve a full cure in close to 100 percent of patients."

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Division of Infectious Diseases
Phone: 617.355.7621
Fax: 617.355.8387

Ken McIntosh, MD
Phone: 617.355.7621
Fax: 617.566.4721