New clinical decision tool for penicillin allergy. A new clinical decision tool accurately identifies low-risk penicillin allergy with a negative predictive value of 96% to 99%, according to an article in the May 1 JAMA Internal Medicine. About 10% of people in the United States report a penicillin allergy, yet when tested, only 1% of people demonstrate a true allergic reaction. And among those who do, 80% lose their sensitivity after 10 years. Identifying true penicillin allergies allows clinicians to treat infections with narrow-spectrum [beta]-lactam antibiotics versus more broad-spectrum antibiotics, decreasing cost, risk of adverse effects such as Clostridioides difficile, and antibiotic resistance. Currently, the only method to determine if someone has a true allergy is through a skin test done by an allergist, followed by a challenge dose. The use of a clinical decision tool offers clinicians a point of care option to identify those at low risk for severe penicillin reactions who can safely be prescribed [beta]-lactams or undergo a penicillin challenge dose.