Xylocaine or Lidocaine is a local anesthetic drug to numb tissues of a specific area. It's also used for treating ventricular tachycardia as well as for performing nerve blocks. Patients with a history of adverse reactions to a specific local anesthetic drug may be termed as allergic. Before determining a suitable pain control technique, the healthcare professional must need to confirm the allergic reactions. A proper dosage is important to administer to restrict unwanted side effects. The Xylocaine allergy reaction is characterized by cutaneous lesions, edema or anaphylactoid reactions. Although allergies as a result of sensitivity to Xylocaine or lidocaine HCI are not common but needs to be treated carefully. The test is conducted on a blood sample to estimate the IgE antibodies level.