Localized Bullous Pemphigoid

Abstract

A man in his 80s presented with a pruritic, focally ulcerated pink plaque with overlying blisters on the left lateral thigh (Figures 1 and 2). This had been the site of an excision 9 months earlier. Over time, pruritic vesicles and bullae developed at the surgical site. Punch biopsies showed a subepidermal bulla with extensive eosinophilic infiltrate on histopathology and linear deposition of C3 and immunoglobulin G (IgG) at the basement membrane zone on direct immunofluorescence, confirming the diagnosis of localized bullous pemphigoid (BP).Figure 2Close-up view of vesicles and bullae at the periphery.View Large Image Figure ViewerDownload Hi-res image Download (PPT) BP is a subepidermal autoimmune blistering disease caused by autoantibodies to hemidesmosome proteins BP180 (BP antigen 2) or BP230 (BP antigen 1). Classically, patients present with pruritic urticarial papules and plaques and tense vesicles and bullae. Diagnosis is made by examination of the tissue and direct immunofluorescence, which show a subepidermal accumulation of eosinophils and linear deposition of IgG and/or C3 in an n-serrated pattern along the basement membrane zone, respectively. Enzyme-linked immunosorbent assay (ELISA) for autoantibodies to the NC16a domain of BP180 and to BP230 is supportive, and anti-BP180-NC16a ELISA may aid in monitoring disease activity during treatment.1Schmidt E. Zillikens D. Pemphigoid diseases.Lancet. 2013; 381: 320-332https://doi.org/10.1016/S0140-6736(12)61140-4Abstract Full Text Full Text PDF PubMed Scopus (705) Google Scholar,2Feliciani C. Joly P. Jonkman M.F. et al.Management of bullous pemphigoid: the European Dermatology Forum consensus in collaboration with the European Academy of Dermatology and Venereology.Br J Dermatol. 2015; 172: 867-877https://doi.org/10.1111/bjd.13717Crossref PubMed Scopus (233) Google Scholar Most cases of BP are generalized. Rarely, it is localized, usually to sites of previous skin injury, surgery, radiation, or venous insufficiency.3Ständer S. Kasperkiewicz M. Thaçi D. et al.Prevalence and presumptive triggers of localized bullous pemphigoid.J Dermatol. 2021; 48: 1257-1261https://doi.org/10.1111/1346-8138.15912Crossref PubMed Scopus (4) Google Scholar Although the pathophysiology of localized BP is not well understood,4Danescu S. Chiorean R. Macovei V. Sitaru C. Baican A. Role of physical factors in the pathogenesis of bullous pemphigoid: case report series and a comprehensive review of the published work.J Dermatol. 2016; 43: 134-140https://doi.org/10.1111/1346-8138.13031Crossref PubMed Scopus (39) Google Scholar topical steroids are first-line therapy and are generally effective.2Feliciani C. Joly P. Jonkman M.F. et al.Management of bullous pemphigoid: the European Dermatology Forum consensus in collaboration with the European Academy of Dermatology and Venereology.Br J Dermatol. 2015; 172: 867-877https://doi.org/10.1111/bjd.13717Crossref PubMed Scopus (233) Google Scholar Our patient was treated with topical clobetasol 0.05% ointment twice daily for 3 weeks with excellent results, and subsequent use as needed to maintain clearance. The authors report no competing interests.