Edematous, highly erythem...

A 56-year-old woman with Fitzpatrick skin type II presented with well-defined, edematous, highly erythematous plaques with overlaying ruptured bullae in photo-distributed areas on the bilateral shins. She also had a history of a stage IV gastrointestinal stromal tumour (GIST) (Fig 1, A-C). After prolonged sun exposure, the patient's anterior shins and dorsal surface of her feet first displayed the rash as a sunburn. The rash got worse over the course of the following three days, and bullae started to appear. Five months before the patient's presentation, oral avapritinib (300 mg) a day was started for the patient's GIST. Following the development of bullae, the patient visited the emergency room and was treated with cephalexin for seven days before being discharged under the suspicion of cellulitis.The following day, with confusion, lethargy, increased bilateral lower extremity edoema, and pain, she visited the emergency room again. This time, she was reported to be febrile, hypoxic, and hemodynamically unstable. In the emergency room, blood cultures were taken to rule out hospital-acquired pneumonia and/or sepsis, and the patient was then started on piperacillin/tazobactam. After being admitted, the patient needed 1 to 4 L of oxygen administered through a nasal cannula. Her chest X-ray revealed modest bilateral pleural effusions and bilateral pulmonary infiltrates on both sides. Dermatology was contacted regarding the newly developed rash on her shins.The drug avapritinib was dropped. The patient was able to wean off her need for oxygen on day four after being admitted. With the improvement of the rash, she was discharged with oral furosemide 40 mg once daily, a recommendation for careful photoprotection and compression stockings, and the start of 0.1 per cent triamcinolone cream. The patient continued to improve and avapritinib was never renewed; ripretinib was eventually begun in its place.