Inclusion Criteria:  Children from ages 2-18 years with a history of parent-reported penicillin allergy.  Exclusion Criteria:  Children with a history of reaction consistent with a severe cutaneous adverse reaction to penicillin as defined as a history of oral blisters, diffuse skin peeling or blisters after taking a penicillin, or having the diagnosis of Stevens Johnson Syndrome, Toxic Epidermal Necrolysis, Drug rash with eosinophilia and systemic symptoms will be excluded. Pregnant and breastfeeding female subjects will be excluded