A patient living in an endemic area for Lyme disease reports a history of a tick bite. Should that patient receive antibiotic prophylaxis?

The question of whether or not patients with tick bites in endemic areas should receive antibiotic prophylaxis is controversial. Randomized controlled trials only support the use of a 200 mg oral dose of doxycycline in a child .8 years of age when all of the following criteria are met: 1) The attached tick can be identified as a nymphal or adult form of Ixodes scapularis that has been attached for >36 hours, estimated by exposure or degree of tick engorgement; 2) prophylaxis can be started within 72 hours of when tick was removed; 3) ecologic information shows that local prevalence of infection of ticks with Borellia burgdorferi is greater than 20%; and 4) doxycycline is not contraindicated.

Wormser GP, Dattwyler RJ, Shapiro ED, et al: The clinical assessment, treatment, and prevention of Lyme disease, human granulocytic anaplasmosis, and babesiosis: clinical practice guidelines by the Infectious Diseases Society of America, Clin Infect Dis 43:1089– 1134, 2006.