[3]: 129  The primary skin lesions are large erythemas (faintly discernible even after confluence), most often irregularly distributed and of a characteristic purplish-livid color, at times with flaccid blisters.

[2]: 554 A rare and severe variation of fixed drug eruption, generalized bullous fixed drug eruption involves blisters and erosions involving at least 10% of the body's surface area, affecting three of the six anatomic sites: the head and neck, the anterior and posterior trunk, the upper and lower extremities, and the genitalia.

[4] Fixed drug eruptions are linked to anti-infective (ß-lactam antibiotics, tinidazole, and acyclovir), analgesics (acetaminophen (paracetamol), mefenamic acid, and metamizole), non-steroidal anti-inflammatory drugs (NSAIDs), anti-epileptic (carbamazepine), psychoactive (barbiturates, codeine, and others), and other miscellaneous medications (omeprazole, contrast media, loratadine, and allopurinol).

[4] In cases where the clinical presentation is unclear, a skin biopsy may be necessary to confirm the diagnosis of GBFDE.

A subepidermal blister or denuded epidermis, vacuolar alterations at the dermo-epidermal junction, and a variable number of necrotic keratinocytes within the lesional intact epidermis are characteristic histopathologic findings of GBFDE.