Oral lichenoid drug eruption due to osimertinib for lung cancer.

INTRODUCTION: Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR) are linked with side effects involving skin and mucosa. Herein, we present a unique case of oral lichenoid drug eruption (LDE) in a patient treated with osimertinib. CASE REPORT: A 75-year-old woman was diagnosed with metastatic EGFR-mutated lung adenocarcinoma, and started on osimertinib 80 mg PO daily. At 24 months of therapy, the patient developed a painful, red, and white striated oral lesion involving the left buccal mucosa and the adjacent buccal aspect of gingivae. Biopsy showed oral LDE. Causality assessment between osimertinib and the oral LDE via Naranjo Adverse Drug Reaction probability scale revealed a score of 5. MANAGEMENT AND OUTCOME: Osimetinib discontinuation was not felt to be in the best interest of the patient. Therefore, diphenhydramine HCL mouthwash every 6 h PRN (before meals) was started. Spicy and hot foods were discontinued. At a four-week follow-up visit, the patient reported moderate improvement in her symptoms. CONCLUSION: Oral LDEs are considered premalignant lesions as they can transform into squamous cell carcinoma; therefore, regular follow-up is needed. Awareness of this potential side effect of osimertinib would also prevent unnecessary (and potentially costly) work-up and lead to its prompt diagnosis and treatment.

Recurrent, multisystem angioedema induced by 5-azacitidine.

INTRODUCTION: 5-azacitidine is a hypomethylating agent (HMA) used for treating myelodysplastic syndrome (MDS) and certain myeloproliferative neoplasms (MPNs). Common side effects include myelosuppression, nausea and injection site reactions. Serious allergic reactions are rare with this class of agents. CASE REPORT: We describe a 71-year-old man with MDS/MPN who developed repeated episodes of angioedema after starting treatment with subcutaneous 5-azacitidine. Angioedema involved multiple body areas including the neck, genitalia, lower back and gastrointestinal system. Causality assessment linked this entity to 5-azacitidine via the Naranjo nomogram questionnaire, by scoring 9. MANAGEMENT AND OUTCOME: 5-azacitidine was discontinued due to recurrent episodes of angioedema that occurred even after dose reduction. Steroids were helpful in terms of reversing this reaction. Afterwards, no further episodes of angioedema have been documented. The patient's thrombocytosis is currently well-controlled with low dose hydroxyurea. DISCUSSION/CONCLUSION: We report herein a unique case of recurrent, multisystem angioedema likely related to 5-azacitidine. The exact mechanism of azacitidine-induced angioedema is not currently known. Symptoms, clinical findings and timing of presentation are not always clear-cut, and it may take more than one cycle of 5-azacitidine before the diagnosis is made. Supportive and symptomatic treatment will be provided based on the severity of the reaction. Future studies may offer more insights into the mechanism underlying this rare and serious, yet intriguing side effect.