Localized Bullous Pemphigoid on the Site of Knee Arthroplasty: A Case Report

Localized bullous pemphigoid is a rare variant of bullous pemphigoid, and its exact etiopathogenesis is yet to be elucidated. We present a case of a 74-year-old Caucasian male with a 3-month history of skin lesions that appeared 9 months after he underwent a knee arthroplasty. Dermatological examination showed several pruritic tense bullae on the right knee, localized around the surgical scar, as well as erosions covered with crusts. The diagnosis of localized bullous pemphigoid was confirmed by direct immunofluorescence test (conventional and split-skin). The patient was treated with potent topical steroids, which led to complete resolution of cutaneous lesions.

We suppose that the occurrence of localized bullous pemphigoid in our patient may be explained by the concept of “immunocompromised district” in which one disease (surgery) caused an immunological alteration which is a predisposing factor for the development of secondary disease such as localized bullous pemphigoid.