Lisinopril-associated bullous pemphigoid in an elderly woman: a case report of a rare adverse drug reaction.

An 87-year-old woman with a long-standing history of hypertension, hypothyroidism and diabetes presented to us with scaly and pruritic vesicles of an erythematous base and crusted surface of 2-month duration. They first appeared on her abdomen and gradually spread to her lower back, thighs, before spreading to her upper and lower limbs. Her lesions were non-painful, aggravated by sun exposure only, and sparing mucous membranes. Nikolsky sign was positive with no discernible fluid-filled bullae. History was remarkable only for a doubling of her Lisinopril dosage 2 months prior to the appearance of her lesions, with no other potential environmental and/or drug triggers recognizable on history taking. In light of the appearance of her lesions after her Lisinopril dose escalation, in the absence of any other discernible triggers, an adverse drug reaction (ADR) was entertained, yielding a corresponding Naranjo ADR probability score of 7. Particularly, drug-induced pemphigus foliaceus was initially suspected given her clinical presentation and the morphology and distribution of her lesions. However, her skin biopsy altered our diagnosis to drug-induced bullous pemphigoid (BP) instead, making this the second case reported to date on Lisinopril-induced BP, and the first to report a dose-response variant of this adverse reaction.