Surprising to many clinicians, less than 20% of purported penicillin allergies are validated in those undergoing skin testing [1]. Reporting a false penicillin allergy is not benign. Patients are deprived of a class of drugs that are effective, available, and potentially lifesaving. In addition, they open themselves to complications from alternative antibiotics that are potentially less effective, have more side effects, and are more expensive. Unnecessary use of newer-generation antibiotics hastens the inevitable emergence of antibiotic-resistant pathogens, with potentially grave long-term public health consequences. Fortunately, in less than 30 minutes, patients with suspected penicillin allergies may undergo skin testing to confirm or disprove an immunoglobulin-E (IgE)emediated allergy with a high level of confidence [2]. As with penicillin, allergic or allergiclike reactions to iodinated intravascular contrast media are well documented and can range from minor cutaneous eruptions to fatal anaphylaxis. The mechanism of reaction remains controversial, with some reactions demonstrating an IgE or T-cell dependence and others not [3]. A gradual adoption of nonionic contrast material has taken place, owing to market forces, patent expiration, and most importantly, an improved safety profile. Use of nonionic iodinated contrast (either low-osmolar or isoosmolar) is the current standard of care [4,5]. Still, among identified culprit drugs, contrast remains second to only antibiotics as a cause of medicationinduced fatal anaphylaxis in the United States [6]. Interestingly, despite the perceived safety of gadolinium-based