Lyme Disease: Ticks, Symptoms, Testing, Treatment and Prevention

Lyme disease is a bacterial infection passed on by the bite of an infected tick. It usually starts with a rash, fever, headache and fatigue. Treated promptly, most people recover quickly; left untreated, the infection can spread to the joints, heart and nervous system.

Cause and the ticks that carry it

In the United States, Lyme disease is usually caused by the bacterium Borrelia burgdorferi. It is spread by blacklegged ticks, also called deer ticks, which are usually found in:

• the Northeast
• the Mid-Atlantic
• the Upper Midwest
• the Pacific coast, especially northern California

The ticks can attach anywhere but are often found in hard-to-see places such as the groin, armpits and scalp. Usually a tick has to stay attached for more than 24 hours to pass on the bacterium.

Most bites happen in the warmer months, April through September, when ticks are most active and people are outdoors more. Bites can happen the rest of the year too, in a warm early fall or an unusually warm late winter, and after a mild winter ticks may come out early.

Symptoms

Early, 3 to 30 days after the bite:

• a red rash called erythema migrans (EM), which most people with Lyme disease get. It spreads over several days, may feel warm, and is usually neither painful nor itchy; as it heals, parts may fade, sometimes giving it a "bull's-eye" look
• fever and chills
• headache and fatigue
• muscle and joint aches
• swollen lymph nodes

If untreated, the infection can spread, with:

• severe headaches and a stiff neck
• more EM rashes elsewhere on the body
• facial palsy, weakness that makes one or both sides of the face droop
• arthritis with severe pain and swelling, especially in the knees and other large joints
• pain that comes and goes in tendons, muscles, joints and bones
• heart palpitations, an irregular heartbeat (Lyme carditis), and bouts of dizziness or shortness of breath
• inflammation of the brain and spinal cord
• nerve pain, or shooting pains, numbness or tingling in the hands or feet

Diagnosis

A provider weighs your symptoms, how likely it is you met infected blacklegged ticks, how likely other illnesses with similar symptoms are, and any lab results. Most Lyme tests look for antibodies, which can take several weeks to develop — so a test done right away can miss an infection that is there, and a second test later may be needed.

Treatment

Lyme disease is treated with antibiotics, and the earlier the better for a full, quick recovery. Some people still have pain, fatigue or trouble thinking for more than 6 months after treatment. This is post-treatment Lyme disease syndrome (PTLDS). Why it happens is not known, and there is no proven treatment — long-term antibiotics have not been shown to help — but the symptoms can be managed. If you still feel unwell after treatment, talk to your provider. Most people improve with time, though it can take several months.

Prevention

Preventing Lyme disease means preventing tick bites:

• Avoid grassy, brushy and wooded areas where ticks live, and keep to the center of hiking trails.
• Use an EPA-registered insect repellent containing DEET, picaridin, IR3535, oil of lemon eucalyptus or para-menthane-diol, and follow the label. EPA evaluates these for safety and effectiveness.
• Treat clothing and gear with a product containing 0.5% permethrin.
• Wear light-colored clothing so ticks show up, with long sleeves and long pants, shirt tucked into pants and pant legs into socks.
• Check yourself, your children and your pets for ticks every day, and remove any carefully.
• After being outdoors, shower, and wash and dry your clothes at high heat.

Sources

Based on "Lyme Disease", MedlinePlus, U.S. National Library of Medicine, drawing on the Centers for Disease Control and Prevention; a work of the United States government in the public domain.