Oral lichen planus pemphigoides: a series of four cases.

OBJECTIVE: Lichen planus pemphigoides (LPP), which is a rare autoimmune blistering mucocutaneous disease of the pemphigoid family of diseases, is characterized by the development of vesiculobullous lesions on or adjacent to the areas of lichen planus (LP). LPP primarily affects the skin, and oral involvement alone is rare. The objective of this case series was to report four new cases of oral LPP. STUDY DESIGN: We present four cases with clinical, histologic, and direct immunofluorescence (DIF) features characteristic of LPP, with three cases having oral involvement only. RESULTS: The four patients (including two males) were aged 49, 50, 51, and 61 years; only one patient had skin lesions. All patients had typical reticular, erythematous, or ulcerative oral LP involving the gingiva and the buccal mucosa. Mucosal biopsies showed features consistent with LP, mucous membrane pemphigoid (MMP), or a combination of both, and DIF studies in all 4 cases showed linear deposition of immunoglobulin G (IgG) and C3 at the interface. CONCLUSIONS: Correlation of clinical findings, routine histopathology, and DIF studies is essential for the diagnosis.