Successful Desensitization to Irinotecan in a Patient with Metastatic Esophageal Squamous Cell Carcinoma and a History of Anaphylaxis in Response to Irinotecan—Case Report and Literature Review

<b>Background:</b><i>Irinotecan</i> is a topoisomerase I inhibitor used for the treatment of various cancers, such as gastrointestinal, pancreatic, pulmonary, ovarian, and cervical cancers. Among chemotherapy agents, it represents a rare trigger of drug hypersensitivity reactions, with few cases being reported until today. <b>Methods:</b> We present the case of a patient with metastatic esophageal cancer and a history of <i>irinotecan</i>-induced grade IV (WAO classification) anaphylaxis. An IgE-mediated reaction was confirmed in our case, as evidenced by a positive intradermal skin test result, and we carried out a successful desensitization protocol, given <i>irinotecan's</i> indispensability in the treatment regimen. Our case underscores the fact that in such situations where the culprit drug is also the only therapeutic option available for such a patient, implementing a desensitization protocol may represent the only viable approach to ensure safe and successful dosing. <b>Results:</b> A comprehensive review of the literature was also conducted to assess previously reported <i>irinotecan</i>-induced hypersensitivity reactions, the utility of skin tests in identifying sensitisation to <i>irinotecan</i>, and the existing desensitization protocols. We found a total of seventeen cases of hypersensitivity reactions to <i>irinotecan</i> in the literature, out of which four provided the skin test results obtained and six performed desensitization protocols for <i>irinotecan</i>. <b>Conclusions:</b> Our literature review highlights that skin testing and desensitization protocols can provide suitable solutions for managing hypersensitivity reactions to <i>irinotecan</i>.