International Journal of Basic & Clinical Pharmacology | December 2021 | Vol 10 | Issue 12 Page 1424 International Journal of Basic & Clinical Pharmacology Dey M et al. Int J Basic Clin Pharmacol. 2021 Dec;10(12):1424-1426 http://www.ijbcp.com pISSN 2319-2003 | eISSN 2279-0780 Case Report Use of levocetrizine in the management of type IV hypersensitivity to lidocaine: a case report Mansi Dey 1 *, Bibhu Prasad Mishra 2 , Abhijeeta Sahoo 2 INTRODUCTION Lidocaine is a drug that is commonly used as a local anesthetic in dentistry. Though a useful local anesthetic, it has been known to cause allergies or other adverse effects that may range from mild symptoms, such as urticaria, erythema, and intense itching to severe reactions in the form of angioedema and/or respiratory distress or even more severe life-threatening anaphylactic responses include symptoms of apnea, hypotension, and loss of consciousness. 1-4 Allergic reactions to local anesthetics are known to involve two types of reactions namely immunoglobulin E (IgE)-mediated type I and T-cell-mediated type IV reactions.4 In cases of suspected allergy to lidocaine, patients should be tested using other local anesthetics, so that the one without any adverse effects can be chosen. In case any local anesthetic without adverse effects is not available, dental treatment can be performed under general anesthesia. 4 1% diphenhydramine is a safe and inexpensive method in patients who are allergic to local anesthesics. 5 In this article, we report a case of type IV hypersensitivity reaction to lidocaine, which was successfully treated using an antihistamine called as levocterizin. CASE REPORT A 29 year old female patient reported to our clinic with a complaint of pain in the upper left region of the mouth. DOI: https://dx.doi.org/10.18203/2319-2003.ijbcp20214511 1 Dey’s Multispeciality Dental Clinic and Oral Surgery Centre, Dehradun, Uttarakhand, India 2 Hi-Tech Dental College and Hospital, Odisa, India Received: 25 October 2021 Accepted: 12 November 2021 *Correspondence: Dr. Mansi Dey, Email: shikhadey2904@gmail.com Copyright: © the author(s), publisher and licensee Medip Academy. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT Lidocaine is a commonly used local anesthetic in the field of dentistry. It has been known to cause allergic reactions, mainly immunoglobulin (IgE)-mediated and T-cell –mediated type IV reactions, which require the use of alternative drugs without adverse effects. Here we present the case of a 29 year old female patient who developed Type IV hypersensitivity reaction in the vicinity of the injection site after the administration of lidocaine local anesthetic for performing exodontia. Levocetrizine tablet was prescribed in order to relieve the symptoms of the reaction. Levocetrizine is a selective, potent, oral histamine H(1) receptor antagonist that is used for the symptomatic treatment of allergic rhinitis and chronic idiopathic urticaria. It has been reported to be effective and generally well tolerated by the patients. In our case also it was able to cure Type IV hypersensitivity reaction to lidocaine without producing any adverse events. Apart from curing allergic rhinitis and urticaria, levocetrizine is a wonderful option for treating Type IV hypersensitivity reaction to a local anesthetic, and it hardly produces any adverse effect. More cases are required to be reported in the future in order to support this article. Keywords: Lidocaine, Allergy, Levocetrizine