We sought the expertise of Dr. Eric Macy. Please see his response below.
"If there is suspected hypersensitivity to clavulanic acid, because Augmentin was the antibiotic associated with the index reaction, and penicillin allergy testing with an oral amoxicillin 250 mg challenge was negative, then an additional oral challenge with amoxicillin/clavulanic acid 250 mg with 1 hour observation can be performed ideally 1 week after the first challenge to ensure there is no delayed onset reaction.
We have needed to do this about 5 times over the past year and have had no positive oral amoxicillin/clavulanic acid 250 mg challenge reactions to date. "
Patricia McNally, MD, FAAAAI