Apalutamide-Induced Toxic Epidermal Necrolysis in a Caucasian Patient with Metastatic Castration-Sensitive Prostate Cancer: A Case Report and Review of the Literature.

Apalutamide is a novel nonsteroidal androgen receptor inhibitor that has been shown to improve outcomes for patients with nonmetastatic castration-resistant prostate cancer and metastatic castration-sensitive prostate cancer when combined with androgen deprivation therapy. Apalutamide-induced skin rash occurred commonly in clinical trials, with 23.8-27.1% of patients experiencing a rash of any grade, and 5.2-6.3% experiencing a rash of grade three or higher. There were no cases of severe cutaneous adverse reactions (SCARs) such as Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN) reported in clinical trials; however, there are rare cases reported in the literature with the majority occurring in Asian patients. An 83-year-old Caucasian male was commenced on apalutamide, combined with degarelix, for the management of metastatic castration-sensitive prostate cancer. During week five of apalutamide treatment, the patient developed a widespread erythematous maculopapular rash. On presentation, the rash affected 80% of his body surface area (BSA) and a diagnosis of a severe cutaneous drug eruption was made. He was commenced on methylprednisolone (MP) therapy. Despite 5 days of MP, the rash continued to deteriorate involving 95% of his BSA. Nikolsky's sign was positive. A diagnosis of overlap SJS/TEN was made, supported by skin biopsy. His SCORTEN score was three. He was then commenced on intravenous immunoglobulin and transferred to the intensive care unit. Over the coming days, the rash began to stabilise, and his steroid dose was weaned. He was discharged from hospital 38 days after rash onset. We report the first suggested case of apalutamide-induced SJS/TEN in a Caucasian patient. We discuss other cases of apalutamide-induced SCARs reported in the literature. Risk factors seem to include low body weight and Japanese race, as well as short time to onset of rash.

Peritoneal Dialysis Exit Site Pyoderma Gangrenosum: A Case Report.

BACKGROUND: Pyoderma gangrenosum (PG) is a rare, chronic inflammatory condition exhibiting mucopurulent or hemorrhagic exudates. The majority of cases are associated with inflammatory bowel disease, rheumatological diseases, and hematological malignancies. In the absence of typical serological markers and specific histopathological changes, the diagnosis is often clinical. Being rare, it is frequently misdiagnosed, which leads to a delay in instituting appropriate therapy. CASE PRESENTATION: We present a 53-year-old male of Aboriginal descent with end-stage renal disease due to diabetes who underwent insertion of a peritoneal dialysis (PD) catheter. Five weeks after PD catheter insertion, he started to notice a painful ulcer surrounded by a bed of erythema. The lesion eventually progressed to a purulent, hemorrhagic ulcer surrounded by a raised, irregular, violaceous border along the entirety of the PD catheter tunnel. There was no history of underlying systemic diseases commonly associated with PG. The catheter was removed, and an elliptical biopsy was taken, which ruled out infection, malignancy, and vasculitis. The changes were felt to be consistent with PG. The patient underwent treatment initially with topical corticosteroids, followed by oral prednisone, which unfortunately worsened his diabetic control; due to this, he was transitioned to cyclosporine, with complete resolution. CONCLUSIONS: Lesions at the PD catheter exit site are usually treated for infections. However, for ulcers that are painful, rapidly expanding, nonhealing, and unresponsive to antibiotics, PG should be considered as a differential diagnosis. This is the first reported case of PG occurring at the exit site of a PD catheter.