Localized Bullous Pemphigoid – A Rare Variant that Poses a Diagnostic Challenge

Most cases of bullous pemphigoid (BP) present with a generalized eruption over extremities and trunk. BP occurring over the localized area of the body is infrequent, with a reported incidence of about 20%. A 70-year-old diabetic male presented with closely arranged tense bullae, large crusts, and erosions over a localized area on the right lower leg. Another 80-year-old male presented with recurrent crops of tense bullae seen exclusively over previous burn scars over the upper thigh region of 2 months’ duration. Differentials of primary bullous dermatosis, acute contact dermatitis, and diabetic bullae were considered. In both cases, histopathology showed subepidermal blister with eosinophilic infiltration and direct immunofluorescence revealed deposition of C3 in a linear pattern, along the dermoepidermal junction favoring a diagnosis of localized BP (LBP). Both cases were managed with conventional treatment leading to complete remission achieved by 3 weeks. A high index of suspicion is warranted to consider LBP in all cases presenting with recurrent localized bullous lesions. Thorough investigations help in the confirmation of diagnosis and aid in the prognostication of disease which is generally favorable.