An 80-year-old woman with adenocarcinoma (cT4N0M1c [BRA, PUL], stage VIB) and harboring an EGFR-sensitizing mutation (L858R) was treated with osimertinib in December 2018 as the first-line treatment, which led to a partial response with marked tumor shrinkage, which was assessed by chest computed tomography after 3 weeks of osimertinib treatment in January 2019. Erythematous papules were observed on the anterior chest wall 32 days after osimertinib induction. Therefore, the patient was referred to the department of dermatology of our institution. Since the dermatologic adverse event (AE) was diagnosed as mild at that time, a topical corticosteroid ointment was prescribed without cessation of osimertinib treatment. However, diffuse erythematous rash rapidly spread over the patient’s trunk (A) and was accompanied by vesicles and purpuric macules; furthermore, targetoid erythema developed on her face (B) after 14 days. Therefore, osimertinib was immediately discontinued. However, the erythema and macules did not alleviate after osimertinib discontinuation and oral prednisolone at a dose of 30 mg was initiated 5 days after osimertinib discontinuation. Four days after the initiation of prednisolone, diffuse erythema with Nikolsky’s sign, general epidermal detachment, erosion and loose blisters developed over her entire body including the face (C). Based on these symptoms, a clinical diagnosis of TEN was made, which was supported by a skin biopsy showing acute interface dermatitis with eosinophil infiltration (D). Therefore, intravenous immunoglobulin (IVIG; 15 g/day) was immediately administered for 4 days. Ten days after IVIG treatment, the erythematous rash on the patient’s trunk disappeared and some scar lesions remained (A). Furthermore, general epidermal detachment, erosion and loose blisters on her face ameliorated with epithelialization (B). Therefore, oral prednisolone was gradually tapered off.
A 70-year-old female patient without other relevant medical history was started on pemetrexed and carboplatin for mesothelioma after vitamin B12 and folic acid supplementation. The patient developed a rash on the anterior chest wall 7 days after the first cycle which persisted despite treatment with loratadine. Four days after the second cycle (14 days after the onset of the rash), the patient was admitted with widespread maculopapular eruptions treated with betamethasone valerate 0.1% cream along with cetirizine 10 mg twice daily. The patient’s additional symptoms were fever, pancytopenia, including neutropenia, seizures and confusion, pulmonary embolism, and nausea. Over the next few days, the rash continued to coalesce and spread. Forty days after the initial onset, 80% of the total body’s surface area (TBSA) was affected with beginning denudation (). Histology showed widespread epidermal necrosis with multiple dyskeratotic keratinocytes. A TEN-like reaction was diagnosed. Treatment with prednisone 50 mg daily to be weaned off by 10 mg every 7 days was initiated along with supportive measures. The patient could be discharged to the community in a stable condition 50 days after the initial rash. Chemotherapy was discontinued and palliative care was initiated due to the sADRs including the diagnosis of a TEN-like reaction.