By Eva Briggs, MD
I’ve seen many tick bites and Lyme disease lately, making this a good time to revisit this condition. There are still many myths and misconceptions.
A corkscrew shaped bacterium from the genus Borrelia causes Lyme disease. Bites from infected ticks, the blacklegged tick (or deer tick, Ixodes scapularis) spreads the disease in our area. The western blacklegged tick (Ixodes pacificus) spreads the disease on the Pacific Coast.
Tiny young nymphal ticks are most likely to spread the disease. They are small (less than 2 millimeter) and easily overlooked. People are more likely to discover the larger adult ticks and remove them early. A tick must attach and feed for 36-48 hours to transmit Lyme disease.
Ticks find their hosts by questing. They attach to plant stems by their rear legs while waving their front legs around. If a host happens by and brushes against the tick, it latches on with its front legs and starts crawling around seeking a suitable place to bite and feed. Ticks don’t jump, fly or drop out of trees.
Once on the host, the tick cuts the skin and inserts its barbed feeding tube. It secretes a cement to keep it firmly in place. The barbs combined with cement makes them hard to remove. Ticks also secrete saliva with anesthetic properties, enabling them to remain attached undetected.
To remove a tick, grasp it firmly close to the skin with tweezers and slowly pull straight upwards. Or use a tick removal tool. It’s a myth that coating a tick with Vaseline or burning it with a match will cause the tick to release. These methods only annoy the tick making it attempt to burrow deeper and may make the tick regurgitate its stomach contents into your blood stream. This increases the chance of disease transmission. If the mouthparts are left behind, you can try to remove them with tweezers. But if they won’t come out, it’s safest to leave them in place and let them work their way out. No need to cause pain, infection or scarring by digging out the mouthparts.
If the tick has been attached more than 24 hours or is engorged, a single dose of doxycycline in adults may reduce the chance that Lyme disease develops. This is called post-exposure prophylaxis but there is currently no recommendation for this in kids.
Lyme disease develops in three stages.
Stage 1 Lyme disease occurs one to 28 days after a tick bite. There may be a low-grade fever. The classic rash is called erythema migraines. It is a flat expanding red rash. It is often painless although it can itch or burn. It often expands for a few days and may have concentric rings like a bullseye. But often it appears uniform in color. The bullseye appearance is not necessary to make the diagnosis in areas where Lyme disease is common (like Central New York) and the person may have been exposed (has not stayed sealed up indoors.)
If a patient has symptoms of stage 1 Lyme disease, blood tests are useless. Blood tests for Lyme measure antibodies produced by the body. But antibody production takes weeks, so the test is likely to be negative at the time of stage 1 Lyme disease. If the patient is treated promptly with antibiotics, the blood test may never turn positive. So, it’s a clinical diagnosis, and if your doctor thinks you have early Lyme disease, take the treatment. Don’t waste time and money on a blood test. And don’t do the test later on, it will not tell you whether the rash was truly Lyme disease or not. Although the rash usually occurs at the site of the tick bite, it can occur elsewhere on the body. There may even be multiple lesions. It is not necessary to remember a tick bite.
Stage 2 Lyme disease, early disseminated Lyme disease, indicates that the bacteria have spread via the blood stream and requires antibiotic treatment. This starts three to 12 weeks after the initial infection. Symptoms include fever, dizziness, headaches, muscle pains and chest pain. Since these symptoms are nonspecific, blood test for Lyme are useful at this stage. Other possible symptoms include an assortment of neurologic symptoms (headache, Bell’s palsy, encephalitis, meningitis), eye symptoms — double vision, inflammation of the cornea) — and arthritis (swollen, red painful joints).
Stage 3 Lyme disease occurs months to years after infection. This also includes neurologic conditions (Bell’s palsy, aseptic meningitis) and arthritis. There may also be heart rhythm disturbances.
Ticks are tenacious and I doubt that it will ever be possible to prevent 100% of tick bites. But there are measures you can take.
Wear long pants and long sleeves when possible. Light colored clothing makes it easier to spot ticks. Treat your clothing with permethrin to repel ticks. Permethrin, when wet, is toxic to cats, but once the treated clothes have dried, it’s safe. Use an effective tick repellant containing DEET, picaridin, IR3535, Oil of Lemon Eucalyptus (OLE), para-menthane-diol (PMD), or 2-undecanone. The Environmental Protection Agency has a list on its website.
Check your body for ticks when you return indoors. Remember to check your clothes as well as your body. Kill ticks in your clothing by washing in hot water or tumbling your clothes in a hot dryer. Cold and medium temperature washing will not kill ticks.
Also remember to check equipment such as daypacks and check your pets. Showering within two hours of coming indoors helps reduce the chance of acquiring tick-borne illnesses.
Eva Briggs is a retired medical doctor who practiced in Central New York for several decades. She lives in Marcellus.