A 22-year-old man comes to the physician because he is concerned about developing Lyme disease. He found a tick on his right leg during a hike in Connecticut five days ago. He describes a two millimeter red dot on his leg where he removed the tick, which has since disappeared. He has no current complaints and a comprehensive review of systems is negative. He has no other medical conditions and takes no medications.
His temperature is 36.5 C (97.7 F), blood pressure is 120/70 mm Hg, pulse is 82/min, and respirations are 14/min. Skin examination shows no rashes and a healed area on his right leg at the site of the tick bite. The remainder of the examination shows no abnormalities.
Which of the following is the best advice for the patient?

Question

A 22-year-old man comes to the physician because he is concerned about developing Lyme disease.  He found a tick on his right leg during a hike in Connecticut five days ago.  He describes a two millimeter red dot on his leg where he removed the tick, which has since disappeared.  He has no current complaints and a comprehensive review of systems is negative.  He has no other medical conditions and takes no medications.
His temperature is 36.5 C (97.7 F), blood pressure is 120/70 mm Hg, pulse is 82/min, and respirations are 14/min.  Skin examination shows no rashes and a healed area on his right leg at the site of the tick bite.  The remainder of the examination shows no abnormalities.
Which of the following is the best advice for the patient?

Quizplus · Accepted Answer

11ec193a_9850_75be_853d_fdf352a0e701_MD0002_00 Lyme disease is caused by Borrelia burgdorferi in the United States and usually presents initially with erythema migrans (EM). However, the infection is typically not transmitted in the first 48-72 hours of tick attachment. Infection risk is increased with tick engorgement and/or attachment for > 72 hours. The first step is tick removal, which is best done with tweezers or protected hands by pulling straight up. Antibiotic prophylaxis is recommended in patients meeting all 5 of the above criteria, usually with doxycycline 200 mg in a single dose (Choice B). If the patient cannot take (or refuses) doxycycline, most physicians do not advise prophylaxis with another antibiotic; instead, observation is recommended with rapid treatment if EM develops. Patients presenting initially with EM do not require serologic testing and should be treated for Lyme disease with antibiotics (e.g., doxycycline, cefuroxime, or amoxicillin). Asymptomatic patients, or those with nonspecific symptoms (e.g., fatigue or myalgias), should not be tested. This patient is asymptomatic, presented > 72 hours after tick removal, and requires no further evaluation at this time. (Choice A) Ceftriaxone is a third generation cephalosporin. It is usually given for second or third stage Lyme disease; however, it is not used for Lyme disease prophylaxis. (Choices C and D) Current guidelines do not recommend serologic testing (i.e., ELISA followed by Western blot) for Lyme disease in asymptomatic patients who report tick bite. IgM antibodies may take 2-6 weeks after infection to appear in the blood; testing in the first 2 weeks may lead to false negatives. Other bacterial infections may cause a false positive ELISA, so testing asymptomatic patients may lead to overtreatment. Educational objective: Asymptomatic patients with tick bites from endemic Lyme disease areas do not require serologic testing. Prophylaxis is recommended in patients who live in endemic areas and have deer tick attachment > 36 hours. Prophylaxis should be initiated within 72 hours of tick removal. Patients with erythema migrans do not need serologic testing, but they should be treated with doxycycline, cefuroxime, or amoxicillin. __________ References: Diagnosis and treatment of Lyme disease (http://www.ncbi.nlm.nih.gov/pubmed/18452688) Efficacy of antibiotic prophylaxis for the prevention of Lyme disease: an updated systematic review and meta-analysis. (http://www.ncbi.nlm.nih.gov/pubmed/20382722)

A 22-Year-Old Man Comes to the Physician Because He Is