A rare case of generalized bullous fixed drug eruption resembling toxic epidermal necrolysis

Generalized bullous fixed drug eruption (GBFDE) is a rare and severe adverse drug reaction characterized by widespread blisters and erosions involving at least 10% of the body surface. GBFDE can mimic Stevens-Johnson syndrome and toxic epidermal necrolysis (TEN), both clinically and histologically. We present the case of a 76-year-old woman with extensive painful blisters and erosions affecting approximately 70% of her skin, including the oral and genital mucosa, accompanied by an impaired general condition, strongly suggesting TEN. However, the absence of Nikolsky's sign, together with slate-gray hyperpigmentation, pointed toward GBFDE, later supported by histopathological analysis. Paracetamol was identified as the most likely causative agent. Following discontinuation of the culprit drug, the patient was treated with high-dose corticosteroids and antibiotics within a multidisciplinary care approach. After 3 weeks of hospitalization, the skin lesions healed with residual hyperpigmentation, and her condition stabilized. Our case highlights the challenge of differentiating between two uncommon severe disorders with overlapping clinical and histopathological features, including extensive epidermal necrosis and subepidermal blistering. Clinical and pathological correlation by experienced physicians is essential for distinguishing GBFDE from TEN because their management strategies differ, impacting both patient outcomes and healthcare costs.