Generalised Bullous Pemphigoid Following Fasciotomy – A Rare Occurrence

Dear Editor, Bullous pemphigoid (BP) is an autoimmune blistering skin disease of the elderly. It occurs in four to six persons per million population per year, with only a few reported cases of localised BP[1] and only two documented cases of generalised BP developing after surgery, to the best of our knowledge.[1,2] Herein, we report a case of generalised BP developing after fasciotomy. A 60-year-old man presented to the dermatology outpatient department with multiple, grouped, clear, fluid-filled bullae on the right lower limb at the site of a healed linear scar [Figure 1] and multiple discrete similar lesions all over the body [Figure 2] that ruptured to form well-defined erosions. The erosions were followed by formation of brownish-black crusting on it. On probing, patient gave a history of swelling and erythema on the right lower limb for which he got a fasciotomy done one month back and was prescribed cefuroxime for 10 days. After 15 days, lesions as described earlier appeared on the healed scar, followed by their spread to both lower limbs, upper limbs, and trunk. The oral mucosa was apparently normal. Patient did not have any comorbidities such as diabetes or a history of chronic drug intake.Figure 1: Multiple tense bullae on both lower limbs with well-defined erosions and a fasciotomy scar on right lower limbFigure 2: Multiple tense vesicles and bullae on upper limbThe results of routine blood cell count, serum creatinine, and hepatic tests were normal. Biopsy showed a sub-epidermal vesicle with abundant eosinophilic infiltrates in the papillary dermis [Figure 3]. Direct immunofluorescence of perilesional skin revealed a linear IgG and C3 deposition at the dermo-epidermal junction [Figure 4]. A diagnosis of BP was accordingly confirmed.Figure 3: H &E staining of a tissue from a bullae showing subepidermal split with eosinophils in 10x magnification, consistent with bullous pemphigoidFigure 4: DIF from perilesionsl skin showing IgG and C3 deposition along basement membrane, consistent with bullous pemphigoidThe patient was started on prednisolone at a dose of 1 mg/kg/day, and the lesions subsided with postinflammatory hypopigmentation and perifollicular hyperpigmentation after 2 weeks. Prednisolone was then tapered and the patient was kept under follow-up. BP is a subepidermal bullous disorder characterized by autoantibodies targeting BP180 and BP230 antigens. It is usually generalised. Radiation, phototherapy, surgical sites, burns, and neurological hemiparesis are common causes of the localised variant.[3] Koebnerisation, alteration of BP180 and BP230 antigens, and exposure of these antigens to the humoral-mediated immunity are the proposed mechanisms for this. Our patient did not have any such predisposing factors. Initial koebnerisation cannot be ruled out, but generalised lesions suggest that it cannot be the only cause. As per one study, local concentration of BP180 and/or BP230 antibodies, inflammatory mediators, and immune cells in the affected extremity increased due to localised edema and vascular congestion, ultimately resulting in the formation of blisters limited to these sites. Studies also suggest that up to seven per cent of unaffected subjects have circulating BP180 and/or BP230 antibodies without any clinical manifestation.[4] Furthermore, one study showed that such antibodies from unaffected subjects can activate immune cells in vitro.[5] However, the pathogenesis is still unclear, and the occurrence of BP after surgery may be merely a coincidental event, especially when one considers other possible triggers, such as drug administration during surgery and even the trauma itself. BP after surgery is usually localised, but it may progress to a generalised form within weeks in the absence of intense, effective medications. In our case, BP occurred at the incision site 1 month after surgery, and no treatment had been started for a month for the bullous lesions. Therefore, early recognition of blistering at the surgery site is essential to ensure timely histopathological assessment and to initiate prompt treatment, potentially preventing disease progression. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.