Β-lactam antibiotic reactions to any β-lactam antibiotic may occur in up to 10% of patients receiving that agent (a small fraction of which are truly IgE-mediated allergic reactions, see amoxicillin rash). Anaphylaxis will occur in approximately 0.01% of patients. There is perhaps a 5%-10% cross-sensitivity between penicillin-derivatives, cephalosporins, and carbapenems; but this figure has been challenged by various investigators. Nevertheless, the risk of cross-reactivity is sufficient to warrant the contraindication of all β-lactam antibiotics in patients with a history of severe allergic reactions (urticaria, anaphylaxis, interstitial nephritis) to any β-lactam antibiotic. A Jarisch–Herxheimer reaction may occur after initial treatment of a spirochetal
Dental antibiotic prophylaxis complications."Standard antibiotic regimens are routinely prescribed and taken before dental procedures to avoid systemic complications secondary to the transient bacteremia caused by manipulation of the oral tissues. Although the ADA, in collaboration with AHA and AAOS have published guidelines specifying those patients who should receive antibiotic prophylaxis, research continues to further define the role dental treatment may play in causing adverse outcomes in these patients. In the past, bacteremia caused by dental procedures (in most cases due to viridans streptococci, which reside in oral cavity), such as a cleaning or extraction of a tooth was thought to be more clinically