Fatal Case of Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis Induced by Doxycycline or Flucloxacillin in a 77-Year-Old Woman: A Rare but Serious Adverse Drug Reaction.

Stevens-Johnson syndrome (SJS) is a serious, potentially life-threatening condition affecting the skin and mucous membranes. This syndrome occurs twice as frequently in females compared to males and affects individuals across all age groups. The most common triggers are drugs. Here, we present a case of SJS linked to doxycycline/flucloxacillin-induced SJS. A 76-year-old woman with Sjögren's syndrome, rheumatoid arthritis (RA), chronic obstructive pulmonary disease (COPD), and osteoarthritis (OA) was referred by her General Practitioner (GP) with a rapidly spreading, itchy, hyperkeratotic rash involving >80% body surface area (BSA), which began on the lower abdomen two days prior. She had received flucloxacillin, doxycycline, and topical steroids, after which the rash worsened. With no known drug allergies, the medications were discontinued, and she was referred for further care. On examination, she had extensive flaky, eruptive lesions with a positive Nikolsky sign. Skin biopsy and immunohistochemistry confirmed widespread epidermal necrosis. A provisional diagnosis of drug-induced toxic epidermal necrolysis (TEN) was made, with flucloxacillin or doxycycline suspected as causative agents. She was started on IV teicoplanin and clindamycin, and received methylprednisolone for three days, followed by intravenous immunoglobulin (IVIG). Dermatology was consulted, and daily swabs and labs were conducted to monitor for infection. Despite intensive care and an initial improvement in Severity-of-Illness Score for Toxic Epidermal Necrolysis (SCORTEN), her condition deteriorated, and she ultimately succumbed to progressive TEN. This case aims to comprehensively document the clinical progression and therapeutic interventions in a fatal presentation of suspected drug-induced TEN. Management of SJS typically involves discontinuation of the likely drug, hospitalization, and supportive care. Though prompt drug withdrawal was implemented, the patient's condition continued to deteriorate, underscoring the severity of the syndrome. This case highlights a rare instance of doxycycline and flucloxacillin-induced SJS in the elderly. It is crucial to identify and recognize this uncommon but potentially life-threatening adverse reaction to doxycycline and flucloxacillin in general practice when prescribed to elderly individuals.