{Reference Type}: Case Reports {Title}: Drug Reaction With Eosinophilia and Systemic Symptoms Syndrome Preceding Toxic Epidermal Necrolysis Secondary to Sildenafil: A Case Report. {Author}: Walterscheid B;Batchinsky M;Tarbox M; {Journal}: Cureus {Volume}: 16 {Issue}: 7 {Year}: 2024 Jul 暂无{DOI}: 10.7759/cureus.63922 {Abstract}: Drug reactions with eosinophilia and systemic symptoms (DRESS) syndrome and Stevens-Johnson syndrome-toxic epidermal necrolysis (SJS-TEN) are reactive entities of aberrant cytotoxic immunologic reactions to exogenous medications. While they are conventionally seen as distinct, separate conditions, we present a case of a rare evolution of DRESS syndrome into SJS-TEN in the setting of simultaneous amoxicillin-clavulanate initiation and long-term sildenafil use in a 66-year-old South Asian female with a known history of prior DRESS syndrome and pulmonary arterial hypertension. We discuss the conditions leading to her unique clinical presentation and provide considerations for future clinical encounters.