Severe Toxicodermia due to Apalutamide: A Case Report of DRESS in an Elderly Adult

Abstract

DRESS syndrome (Drug Reaction with Eosinophilia and Systemic Symptoms) is a severe toxicoderma characterized by a hypersensitivity reaction to medications, accompanied by eosinophilia and systemic manifestations. Apalutamide, a selective androgen receptor inhibitor approved for the treatment of prostate cancer, has been associated with various dermatological complications. This study aims to document the clinical case of a geriatric patient with stage IV prostate cancer who developed toxicoderma after initiating treatment with apalutamide. An 81-year-old patient with a diagnosis of stage IV acinar adenocarcinoma of the prostate presented with a 15-day history of generalized papular lesions and general malaise, without improvement despite the use of oral antihistamines. The patient reported having started apalutamide four weeks prior.

Physical examination revealed facial edema and erythema, with erythematous and edematous plaques with a desquamative surface covering more than 50% of the body surface. Laboratory results showed eosinophils at 3040 cells/µL and a rise in baseline creatinine from 1.76 mg/dL to 2.4 mg/dL. The RegiSCAR score was 3 points, classifying it as a possible case of DRESS. A skin biopsy revealed a dermoepidermal hypersensitivity reaction with eosinophilic infiltration. The patient improved with oral and topical corticosteroids and the discontinuation of apalutamide. The diagnosis of DRESS was confirmed, and the patient remains under follow-up by the Oncology service. Several medications have been associated with the development of DRESS syndrome. Early recognition allows for the suspension of the causative treatment, thus reducing patient morbidity and mortality. It also facilitates a timely change in oncological therapy in advanced stages, preventing the patient from being left without adequate cancer management.