When a blacklegged tick bite is more than a bite

Reports of known blacklegged tick bites appear to be a source of confusion for some clinicians. Only 20% or so of all patients with Lyme disease were aware of the bite that caused their infection. When a tick bite history is present, it is crucial to consider the bite in the broader clinical context. This activity will help physicians distinguish between symptomatic and asymptomatic blacklegged tick bites.

Learning objectives:

1. Be able to distinguish between asymptomatic and symptomatic blacklegged tick bites 
2. Understand general management principles for asymptomatic and symptomatic blacklegged tick bites.

This enduring material activity has been reviewed and is acceptable for credit by the American Academy of Family Physicians. The term of approval begins on 07/27/2020 and expires 07/26/2021. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Approved for 0.25 AAFP-prescribed credits.

Evidence-based bibliography for further study

• https://phil.cdc.gov/QuickSearch.aspx?key=truekey=true 

• https://www.cdc.gov/ticks/tickbornediseases/tick-bite-prophylaxis.html. Last accessed March 30, 2019. 

• Steere AC, Sikand VK. The Presenting Manifestations of Lyme Disease and the Outcomes of Treatment. N Engl J Med 2003; 348:2472-2474. 

• Steere AC, Dhar A, Hernandez J, Fischer PA, Sikand VK, Schoen RT, et al. Systemic Symptoms without Erythema Migrans as the Presenting Picture of Early Lyme Disease. Am J Med 2003;114:58-62. 

• Smith RP, Schoen RT, Rahn DW, et al. Clinical characteristics and treatment outcome of early Lyme disease in patients with microbiologically confirmed erythema migrans. Ann Intern Med. 2002 Mar 19;136(6):421-428. 

• Tibbles CD, Edlow JA. Does this patient have erythema migrans? JAMA. 2007 Jun 20;297(23):2617-27. 

• Magid D, Schwartz B, Craft J, Schwartz JS. Prevention of Lyme disease after tick bites. A cost-effectiveness analysis. N Engl J Med. 1992 Aug 20;327(8):534-41. 

• Cameron D, Maloney E, Johnson L Evidence assessment and guideline recommendations in Lyme disease: the clinical management of known tick bites, erythema migrans rashes and persistent disease. Expert Rev Anti Infect Ther 2014 Sep; 12(9): 1103-1135. 

• Piesman J, Hojgaard A. Protective value of prophylactic antibiotic treatment of tick bite for Lyme disease prevention: an animal model. Ticks Tick Borne Dis. 2012 Jun;3(3):193- 196. 

• 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 2006; 43(9):1089-1134.