Preventing Tick Bites and Lyme Disease
With the onset of summer and increase in outdoor activities comes an increased risk of Lyme disease. The Mid Atlantic is one of the highest risk areas of the country. Transmission usually occurs via the bite of an infected Ixodes Scapularis tick. They're typically small in size, have dark coloration. They're about the size of a poppy seed. In this area, there is also a high occurrence of lone star ticks, which are much larger and often have a white spot on their back. It is important to know that the nymph stage of the Ixodes ticks are the most likely to transmit Lyme, whereas the adult male or female (much larger, about the size of a sesame seed) do not typically carry the infection.
The risk of transmission increases with the tick attachment duration typically requiring at least 36 hours for Borrelia burgdorferi (the bacteria that causes Lyme disease) to be transmitted. Symptoms of Lyme disease typically develop 3 to 30 days after a tick bite. Erythema migrans is the classic bull's eye rash and typically appears within 7 to 14 days. However, some patients may also experience flu-like symptoms, lymph node swelling, and in cases where disease is disseminated, may present with multiple rashes, joint pain, or a facial palsy.
Diagnosis is primarily made clinically with the presence of erythema migrans and approximately 70 to 80 percent of patients presenting with this finding. In cases where a tick is able to be removed, the sample can be sent to the tick research lab for evaluation and confirmation that the tick contains the bacteria. Testing is not recommended immediately after the tick bite or for people without symptoms as the tests are not accurate.
If no rash is seen, a two step test no less than 2 weeks after the suspected bite is performed. The first is a screening test and if positive or unclear, a second more comprehensive test called a Western Blot is performed. This test detects antibodies to Lyme disease which take at least 2 weeks to develop. If a patient is initially negative but is still having symptoms they should be retested in 2 weeks.
For treatment, we have a few options. If a patient identifies an Ixodes tick, it is attached for 36 hours and treatment is started within 72 hours then a single dose of Doxycycline is effective. For patients with erythema migrans rash without systemic symptoms, a 10 day course of Doxy is used. Patients who have more systemic disease (i.e. arthritis, bell’s palsy etc) a 21 day course is needed. Treatment is very successful with the protocols listed above.
As with any medical condition, prevention is key. If you are in a tick prone area be sure to wear light colored clothing with long sleeves and pants. Permethrin can be applied to clothing (only) for an added layer of protection. DEET can be applied to the skin. Once you leave the area perform a thorough check of the entire body including the groin, arm pits, scalp and behind the ears. As always if you’re concerned about a tick bite contact your physician.
