Background: Lichen planus pemphigoides LPP , an association between lichen planus and bullous pemphigoid lesions, is a rare subepithelial autoimmune bullous disease. Mucous membrane involvement has been reported previously; however, it has never been specifically studied.
Methods: We report on 12 cases of LPP with predominant or exclusive mucous membrane involvement. Our systematic review of the literature, performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, highlights the clinical and immunological characteristics of LPP, with or without mucous membrane involvement.
Results: Corticosteroids are the most frequently used treatment, with better outcomes in LPP with skin involvement alone than in that with mucous membrane involvement. Our results suggest that immunomodulators represent an alternative first-line treatment for patients with predominant mucous membrane involvement.
In addition to clinical lichenoid lesions and tense blisters and histological lichenoid changes and subepidermal split findings, the gold standard for the diagnosis of LPP is the detection of autoantibody deposits along the dermalβepidermal junction DEJ using direct immunofluorescence DIF on perilesional skin biopsies, as first reported by Stingl et al. Using immunoblotting IB , Ogg et al. Additional studies suggested that LPP is not a simple association between LP and BP and highlighted its heterogeneity regarding targeted antigens.
Zillikens et al. Moreover, using recombinant proteins covering the entire NC16 domain of BP, the same team identified more subtle differences in the epitope specificity of circulating autoantibodies in the sera of patients with LPP compared with those with mucous membrane pemphigoid MMP , BP, and pemphigoid gestationis PG 6.
