[Bullous autoimmune dermatoses of the mucous membranes]

Pemphigus and pemphigoids: Clinical presentation, diagnosis and therapy

Pemphigus and pemphigoid are two potentially life-threatening groups of autoimmune diseases, characterized by autoantibodies targeting structural components of desmosomes or hemidesmosomes, respectively. Affected patients typically show itchy/painful plaques or blistering skin lesions and/or impairing mucosal blistering and erosions, which may strongly impact their quality of life. Since the milestone work of Walter Lever in 1953, who differentiated these two groups of diseases by histopathological analysis of the level of antibody-mediated skin cleavage, enormous progresses occurred. Achievements made in laboratory diagnostics now allow to identify antigen specific structural proteins of the skin that are targeted by pathogenic autoantibodies. These progresses were accompanied by an increased understanding of the pathogenesis of these diseases thanks to the establishment of animal models reproducing disease and on studies on skin and blood of affected individuals, which have been leading to novel and disease-specific treatments. Yet, given their phenotypical overlap with more common dermatological diseases, correct diagnosis and appropriate treatment are often delayed, in some cases leading to irreversible sequelae, including organ dysfunction (i.e., loss of vision in mucous membrane pemphigoid). Here, we provide a concise overview of the clinical appearance, diagnosis and therapeutic management of pemphigus and pemphigoid diseases.

Pemphigus- und Pemphigoid-Erkrankungen: Klinik, Diagnostik und Therapie: Pemphigus and pemphigoids: Clinical presentation, diagnosis and therapy

Pemphigus und Pemphigoid sind seltene Autoimmunkrankheiten der Haut mit potenziell lebensbedrohlichem Verlauf. Autoantikörper gegen epidermale und junktionale Strukturproteine (Desmosomen sowie Hemidesmosomen) führen bei Betroffenen typischerweise zu juckenden, schmerzhaften Plaques oder Blasen an der Haut und/oder Blasenbildung und Erosionen der Schleimhäute mit möglicher Einschränkung der Lebensqualität. Seit der bahnbrechenden Arbeit von Walter Lever im Jahr 1953, dem es gelang, mittels histopathologischer Untersuchung diese beiden Krankheitsgruppen anhand des Musters der Antikörper‐vermittelten Blasenbildung zu differenzieren, wurden enorme Fortschritte im Verständnis der Erkrankungen erzielt. Die Errungenschaften in der Labordiagnostik ermöglichten die Identifikation von Zielstrukturen zur präzisen Unterscheidung verschiedener Varianten der bullösen Autoimmunerkrankungen. Diese Fortschritte gingen dank der Entwicklung von Tiermodellen mit einem besseren Verständnis der Pathogenese einher. Außerdem haben Studien an Haut und Blut betroffener Patienten zu neuen und krankheitsspezifischen Behandlungen geführt. Aufgrund ihrer Seltenheit und der klinischen Ähnlichkeit mit anderen dermatologischen Erkrankungen verzögern sich die korrekte Diagnosestellung und die Einleitung einer entsprechenden Therapie häufig, was in einigen Fällen zu irreversiblen Folgeerscheinungen, einschließlich Funktionsstörungen von Organen (zum Beispiel Verlust des Sehvermögens beim Schleimhautpemphigoid) führt. Wir geben hier einen Überblick über das klinische Erscheinungsbild, den Diagnosealgorithmus und das therapeutische Management von Pemphigus‐ und Pemphigoid‐Erkrankungen.

[Management of bullous pemphigoid and mucous membrane pemphigoid]

BACKGROUND

Bullous pemphigoid (BP) is the most common blistering autoimmune dermatosis and, as an age-associated disease, is also the bullous dermatosis with the highest increase in incidence in recent years due to demographic developments. Mucous membrane pemphigoid (MMP), which is less common, is a clinically and immunopathologically heterogeneous blistering autoimmune dermatosis characterized by blisters and erosions on mucous membranes.

OBJECTIVE

This work summarizes the manifold clinical characteristics of both diseases and provides an up-to-date overview of diagnostics and therapy of BP and SHP.

MATERIALS AND METHODS

A selective literature search was carried out.

RESULTS

While eczematous, urticarial, or bullous lesions on the integument are typical for BP, MMP is characterized by pronounced, erosive mucosal changes orally, ocularly, genitoanally, tracheally or esophageally and, at most, only minor skin involvement. For diagnosis, the combination of histology, direct immunofluorescence microscopy, and serological detection of autoantibodies against the hemidesmosomal proteins BP180 and BP230 and, in MMP, also against laminin 332 is important. New pathophysiological findings and therapeutics have recently significantly expanded the range of treatment options.

CONCLUSION

Due to the comorbidities of the usually elderly BP patients and the often multiple affected mucous membranes in MMP, with the risk of developing irreversible complications such as strictures and synechiae, interdisciplinary diagnosis and therapy is often required.

Case report: Detection of anti-bullous pemphigoid antigen 180 antibodies in a patient with Behçet’s disease

Behçet’s disease (BD) is a systemic inflammatory disease of unknown etiology. BD is characterized by relapsing oral and genital ulcers, several different cutaneous features, relapsing bilateral uveitis, and involvement of internal organs, showing vascular, gastrointestinal, and neurological manifestations. Serologically, BD is not characterized by disease-specific autoantibodies. In fact, only laboratory markers of inflammation, such as C-reactive protein, may be increased in association with increased disease activity. Bullous pemphigoid (BP) is an autoimmune disease characterized mainly by tense blisters and urticaria-like plaques on the skin. In addition, BP can involve oral mucosa in up to 20% of patients. Patients with BP show serum IgG autoantibodies against BP antigen 180 (BP180) and/or BP antigen 230 (BP230). Tissue-bound autoantibodies can be visualized as linear IgG staining along the basement membrane by direct immunofluorescence microscopy. In this report, we first described a young patient with BD who showed IgG autoantibodies against BP180 without developing blisters or urticaria-like plaques.