Question of the Week # 5

A 30 y/o pregnant woman has a one week history of a slowly enlarging red lesion on her right thigh. She reports having gone on a camping trip about 3 weeks ago and now recalls that she removed a tick from the site of the lesion. An ELISA test is negative for Lymes. Upon further questioning, she also reports contact with poison Ivy like  bushes during the same camping trip :

Archer USMLE Step 3

What is the next step?
A. Re-assurance
B. Ampicillin
C. Doxycycline
D. Western blot testing
E. Topical Corticosteroid
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12 Thoughts on “Question of the Week # 5

  1. wasif sheikh on August 1, 2010 at 3:44 am said:

    B.

  2. Vishakha on August 3, 2010 at 4:18 am said:

    B

  3. Cesar on August 4, 2010 at 5:47 am said:

    B ampicillin the elisa test is in the window period, it is not yet positive
    I prefer to treat the patient to prevent cardiac or neuro complications

  4. I assumed it is B also, but why no reply from Archer yet?

    Dr Red, can you confirm that the answer here is B?

  5. Ans. B

    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.

  6. raju on June 6, 2011 at 5:51 pm said:

    BBBBBBBBBBBB

  7. ISIDORE on June 28, 2011 at 11:21 pm said:

    I agree tetracycline for non prego &Ampicillin for prego
    this is the bull’s eye rash

  8. Syed on June 20, 2012 at 9:06 pm said:

    Good one..

  9. Mehwish Mufti on February 18, 2013 at 6:19 pm said:

    b

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