This guideline has been initiated by the task forceAutoimmune Blistering Diseasesof the European Academy of Dermatology and Venereology, including physicians from all relevant disciplines and patient organizations. It is a S3 consensus‐based guideline that systematically reviewed the literature on mucous membrane pemphigoid (MMP) in the MEDLINE and EMBASE databases until June 2019, with no limitations on language. While the first part of this guideline addressed methodology, as well as epidemiology, terminology, aetiology, clinical presentation and outcome measures in MMP, the second part presents the diagnostics and management of MMP. MMP should be suspected in cases with predominant mucosal lesions. Direct immunofluorescence microscopy to detect tissue‐bound IgG, IgA and/or complement C3, combined with serological testing for circulating autoantibodies are recommended. In most patients, serum autoantibodies are present only in low levels and in variable proportions, depending on the clinical sites involved. Circulating autoantibodies are determined by indirect IF assays using tissue substrates, or ELISA using different recombinant forms of the target antigens or immunoblotting using different substrates. The major target antigen in MMP is type XVII collagen (BP180), although in 10–25% of patients laminin 332 is recognized. In 25–30% of MMP patients with anti‐laminin 332 reactivity, malignancies have been associated. As first‐line treatment of mild/moderate MMP, dapsone, methotrexate or tetracyclines and/or topical corticosteroids are recommended. For severe MMP, dapsone and oral or intravenous cyclophosphamide and/or oral corticosteroids are recommended as first‐line regimens. Additional recommendations are given, tailored to treatment of single‐site MMP such as oral, ocular, laryngeal, oesophageal and genital MMP, as well as the diagnosis of ocular MMP. Treatment recommendations are limited by the complete lack of high‐quality randomized controlled trials.

This guideline on mucous membrane pemphigoid (MMP) has been elaborated by the Task Force for Autoimmune Blistering Diseases of the European Academy of Dermatology and Venereology (EADV) with a contribution of physicians from all relevant disciplines and patient organizations. It is a S3 consensus‐based guideline encompassing a systematic review of the literature until June 2019 in the MEDLINE and EMBASE databases. This first part covers methodology, the clinical definition of MMP, epidemiology, MMP subtypes, immunopathological characteristics, disease assessment and outcome scores. MMP describes a group of autoimmune skin and mucous membrane blistering diseases, characterized by a chronic course and by predominant involvement of the mucous membranes, such as the oral, ocular, nasal, nasopharyngeal, anogenital, laryngeal and oesophageal mucosa. MMP patients may present with mono‐ or multisite involvement. Patients’ autoantibodies have been shown to be predominantly directed against BP180 (also called BPAG2, type XVII collagen), BP230, laminin 332 and type VII collagen, components of junctional adhesion complexes promoting epithelial stromal attachment in stratified epithelia. Various disease assessment scores are available, including the Mucous Membrane Pemphigoid Disease Area Index (MMPDAI), the Autoimmune Bullous Skin disorder Intensity Score (ABSIS), the ‘Cicatrising Conjunctivitis Assessment Tool’ and the Oral Disease Severity Score (ODSS). Patient‐reported outcome measurements (PROMs), including DLQI, ABQOL and TABQOL, can be used for assessment of quality of life to evaluate the effectiveness of therapeutic interventions and monitor disease course.

Pemphigus is a group of blistering disorders characterized by the formation of intraepithelial blisters in skin and mucous membranes induced by the binding of circulating autoantibodies to intercellular adhesion molecules. The pathogenesis is complex and not fully understood; however, genetic predisposition and various triggers are widely accepted as key factors in pemphigus development. A few cases of new‐onset pemphigus following coronavirus disease 2019 (COVID‐19) vaccination have already been published. The present paper reports a total of two cases of pemphigus foliaceous and three cases of pemphigus vulgaris that occurred following vaccinations against COVID‐19, with anamnestic, clinical, and diagnostic data collection suggesting assumptions over a possible causal correlation.

Linear IgA bullous dermatosis (LABD) is a mucocutaneous autoimmune blistering disease affecting both adults and children. It is caused by IgA antibodies targeting multiple antigens along the basement membrane zone, leading to disruption of dermoepidermal junction and development of bullous lesions which often presents in characteristic arrangement. Although most LABD cases have been reported to be idiopathic, different triggers have been described, including several drugs and infection. However, the occurrence of vaccine-induced cases of LABD is not widely known and accepted due to the few reports available. We present two cases of LABD occurred following different triggers, rising the suspicion for a possible pathogenetic role of vaccines.

Cutaneous vasculitis (CV) is an inflammatory skin-limited vascular disease affecting the dermal and/or hypodermal vessel wall. From the pathogenetic point of view, idiopathic forms are described as well as the induction from various triggers, such as drugs, infections, and vaccines. Following SARS-CoV-2 pandemic outbreak, cases of CV induced by both COVID-19 and COVID-19 vaccinations have been reported in literature. The aim of our work was to collect multiple cases available in the literature and analyze the frequency of the different forms of induced vasculitis, as well as their histological and immunopathological features. Although rare, CV induced by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and vaccines may provide interesting insights into the pathogenesis of these inflammatory processes that may in the future be useful to understand the mechanisms underlying cutaneous and systemic vasculitis.