Immediate allergy against glucagon-like peptide-1 receptor agonist liraglutide

Dear Editor I have read the article titled “Hypersensitivity to liraglutide: A case report” by Marino-Fernández et al. [1] with great interest. However, while reading the case report, I have some questions about the diagnostic and treatment process of this patient. Clarification of these questions regarding this case report would help to better understand the study. There are confusing statements when you read about the performance of skin tests and the evaluation of the intradermal and epidermal tests. For example, intraepidermal 1/1, was this 1/1 undiluted, that is, 1/2 diluted or not diluted at all? In addition, the epidermal skin prick test is called “intraepidermal,” causing misunderstanding. There are 2 types of skin testing utilized in the clinical practice of allergy: percutaneous testing (prick or puncture) and intracutaneous testing (intradermal) [2]. Again, in the interpretation of the intradermal test, “acute positive reaction” is mentioned, and it is not correctly stated whether an early reading of the intradermal test is meant here or another reaction [1]. I think based on this test, the immediate reaction is mentioned in the keywords [1], but this patient did not have an obvious clinical finding of immediate hypersensitivity reaction as described. The rash is said to have started at the site of local injection and then spread to the abdomen, but this was not immediate. Here, I think different types of hypersensitivity are also responsible beyond being IgE-mediated. Even if this reaction was thought to be IgE-mediated, other hypersensitivity mechanisms should have been investigated by patch testing. In addition, although the patient did not meet the criteria for desensitization, they offered it to the patient, but the endocrine team and the patient did not accept it. In the discussion, the authors contradicted themselves by saying that this patient did not deserve desensitization [1]. Figure 1 is not well understood [1]. Also, I think the control test with physiological saline solution for intradermal does not appear to be negative, although it is said to be negative [1]. The initial recommended dose of Liraglutide is 0.6 mg once daily for the first week in the package leaflet. In this case, it is understood that 1.2 mg was started [1]. The starting dose appears to be incorrectly high, and it is not said where this dose was administered subcutaneously. Could these have played a role in the development of this reaction? Such side effects seen in this case are already written in the package leaflet as common and uncommon side effects and are well known. The package insert lists common side effects as injection site reactions (such as bruising, pain, irritation, itching, and rash), and less common are allergic reactions, including skin rash. These commonly reported and known side effects make the case not unique [3]. In the cases reported in the literature, either the drug Liraglutide was changed or such rashes disappeared over time [4]. However, I agree that it is necessary to understand whether these side effects are IgE-mediated or not. In addition, individualized management is not involved in this case either [1]. Because the person’s original medication was not continued or modified in any way. The reason why the patient was started on Liraglutide does not disappear even if this drug is stopped. Tolerable alternative medicines that can be tested and used, for example, semaglutide, have not been identified [4]. In conclusion, I would like to thank the authors for this beautiful case report that allowed us to discuss hypersensitivity reactions to glucagon-like peptide-1 receptor agonists. Conflicts of interest The authors have no financial conflicts of interest.