Abstract
Background: Local anesthetics (LA) are widely used in medicine and are generally well tolerated. Although most adverse reactions are nonallergic, LA are a frequent reason for allergy consultation.Objective: We want to expand the differential diagnosis of adverse reactions to LA by presenting rare diagnoses.Methods: We present here two patients with similar clinical presentations, namely skin necrosis after local anesthesia with lidocaine, but with two different final diagnoses.Results: For Patient 1, skin necrosis was imputed to the vasoconstrictor effect of epinephrine in a patient with vascular background aggravated by heavy consumption of tobacco and cannabis. Patient 2 final diagnosis was Nicolau syndrome (embolia cutis medicamentosa), a cutaneous necrosis at the site of injection.Conclusions: The allergist should be aware of these diagnoses and include them in the differential diagnosis of local anesthetic hypersensitivity.