In vivo confocal microscopy of mucous membrane pemphigoid, a new tool for the diagnosis. Reporting 6 cases

Abstract

AbstractPurpose Mucous membrane pemphigoid (MMP), previously known as cicatricial pemphigoid, is an autoimmune disease characterized by linear deposition of IgG and IgA along the epithelial basement membrane zone in direct immunofluorescence (DIF). DIF requires mucosal biopsy, which can worsen the condition by triggering an inflammatory response of the mucosa, especially the conjunctiva. We assess in vivo confocal microscopy (IVCM) for the detection of the pathognomonic basement membrane cleavage zone (BMCZ) in MMPMethods Six patients (4 M, 2 W), suffering from ocular and/or oral MMP were tested with IVCM, using the handheld Vivascope 3000. Three patients had ocular involvement, 2 oral involvement, and 1 had both.Results Mean age was 76 years old. Out of the 4 patients with ocular involvement, 2 patients had active conjunctivitis and 2 patients had cicatricial lesions. A BMCZ was identified in both patients with active conjunctivitis, while none was observed in those with cicatricial lesions. All 3 patients with oral involvement had desquamative gingivitis with marked BMCZ.Conclusion IVCM is non‐invasive and reliable for the diagnosis of MMP. Conjunctival fornix biopsy is at high risk of symblepharon. These biopsies are often performed blindly as the pathological zones are barely visible clinically. IVCM enables the observation of the whole inflammatory surface of the conjunctiva and gum. To our knowledge, these are the first 2 cases of patients with conjunctival BMCZ clearly identified with IVCM.