Review Question - QID 100516

Ampicillin ( Ans.B) is the most appropriate antibiotic for this pregnant woman with early stage Lymes disease. The patient has erythema chronicum migrans which is pathognomonic of early lymes disease. ELISA may be negative in early stage LYME disease and diagnosis must be based on clinical history. No further testing is necessary in the presence of such strong clinical history.
Ans. A is inappropriate and not treating lyme disease can be lethal to the patient.
Ans. C is an appropriate first choice for non pregnant patients with lyme disease. Doxycycline is classified as pregnancy category D. Tetracycline exposure during the second or third trimester can cause permanent discoloration of the teeth.
Ans. D is incorrect. Western blot is only used to confirm a positive ELISA test because ELISA is associated with a high rate of false positive results. In the absence of strong clinical suspicion, both ELISA and Western blot must be positive in order to diagnose lyme disease. Such testing is especially useful when someone is suspected to have late lyme disease manifestations. ELISA in this patient is negative. It is not required in this case to diagnose early lyme disease given that she has strong clinical features to support the diagnosis.