Abstract
Bullous dermatoses include the rare, chronic autoimmune diseases pemphigus vulgaris and bullous pemphigoid. These diseases are traditionally taught to be differentiated by the presence of mucosal lesions (pemphigus vulgaris) and bullae without mucosal involvement (bullous pemphigoid). In the clinical setting, however, these diseases often contain overlapping features that present challenges to care teams without access to dermatologic care and leave patients without a clear treatment pathway. The ability to differentiate these two diseases clinically is imperative as it determines treatment regimens which when applied can mitigate unnecessary morbidity and mortality. Identifying these conditions clinically for the correct treatment also allows providers to rely less on laboratory assessments which are often unavailable or may take considerable time to result. This report details the clinical course of a patient who presented with an undifferentiated bullous dermatitis with features of both pemphigus vulgaris and bullous pemphigoid and aims to highlight the features of presentation which overlap between pemphigus vulgaris and bullous pemphigoid and those which are more characteristic for one over the other.