Osimertinib-Induced Toxic Epidermal Necrolysis - A Case Report.

Purpose: To investigate the rare side effects of Osimertinib in a case of toxic epidermal necrosis.

Case Presentation: We report on a case of a 44-year old woman with lung adenocarcinoma harboring an EGFR-sensitizing mutation who was treated with Osimertinib as the second-line treatment. Ten days after Osimertinib initiation, a diffuse erythematous rash rapidly spread over the patient's trunk along with vesicles and purpuric macules; furthermore, she developed erythema and exfoliation on the face and trunk and severe mucositis. Toxic epidermal necrolysis (TEN) is life-threatening dermatologic adverse event, caused by a delayed-type drug hypersensitivity reaction. Although skin toxicity is common during treatment with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), Osimertinib-associated TEN is very rare.

Results: Treatment with systemic steroids and immunoglobulin as well as supportive treatment led to an improvement of her general wellbeing, followed by a remarkable recovery.

Conclusions: Although the clinical use of Osimertinib is becoming widespread, the side effects may not be fully understood. Clinicians should indeed pay more attention to the occurrence of side effects and be prepared to deal with them in timely manner.