Post Exposure Antimicrobial Prophylaxis to Prevent Lyme Disease may be Beneficial in Certain Cases

A single dose of doxycycline can lower the risk of Lyme disease when:

• The tick bite occurred where Lyme disease incidence is high or in an area where >20% of ticks are infected with Borrelia burgdorferi. 
• The attached tick can be identified as an adult or nymphal blacklegged tick.  
• The estimated time of attachment is ≥36 hours based on the degree of tick engorgement with blood or likely time of exposure to the tick.
• Prophylaxis can be started within 72 hours of tick removal.
• The patient has no contraindication to doxycycline.