USMLE Forum - Largest USMLE Community

A 34-year-old pregnant female receives her prenatal
care from you. She has positive laboratory testing for
syphilis. She has a history of possible penicillin allergy
as a child. The patient is unable to recall the specifics
regarding her reaction.

What is the best treatment option for this
patient?

A) Give a test dose of penicillin.
B) Give an alternative antibiotic.
C) Proceed with penicillin desensitization.
D) Skin test for penicillin; if positive, perform penicillin
desensitization procedure.
E) Skin test for penicillin; if negative, give penicillin at
full treatment dose.

C...

.C.

think again , i knew u r going to select C, but it isnt the right one

D....

D or E

-d-

ummmm.....shucks..i guess maybe D,,

Discussion
The correct answer is D. This patient requires treatment
for syphilis for which penicillin is the drug of
choice. The best treatment option would include skin
testing for penicillin followed by desensitization if skin
testing is positive. If skin testing is positive, there is
approximately a 60% risk of an immediate reaction to
penicillin. If skin testing is negative, there is still a 2%
risk of an immediate reaction. Therefore, prior to full
treatment doses, a test dose of penicillin (answer E)
should be given to ensure that the patient can tolerate
the medication. Penicillin desensitization should not
be performed without skin testing since a costly desensitization
procedure may be avoided if skin testing is
negative. Test-dosing with penicillin would not be safe
without negative skin testing, as very little drug would
be necessary to bring about a severe IgE-mediated
reaction if true penicillin allergy does exist.

more information for your own information to read, it is helpfull

HELPFUL TIP: The large majority of patients
who report penicillin (and other) allergies are
not truly allergic. In the case of penicillin, 0.5% of
those with reported penicillin allergy had skin
reactions and

HELPFUL TIP There is essentially no cross
reactivity between penicillin and third-generation
cephalosporins. As long as the patient did not
have true anaphylaxis, feel comfortable using
these drugs in penicillin-allergic patients.