Most cases are easy to diagnose
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
"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."