Linear IgA disease: clinical presentation, diagnosis, and pathogenesis

S2k guidelines on diagnosis and treatment of linear IgA dermatosis initiated by the European Academy of Dermatology and Venereology

INTRODUCTION

Linear IgA dermatosis (LAD) is a rare subepidermal autoimmune bullous disease (AIBD) defined by predominant or exclusive immune deposits of immunoglobulin A at the basement membrane zone of skin or mucous membranes. This disorder is a rare, clinically and immunologically heterogeneous disease occurring both in children and in adults. The aim of this project is to present the main clinical features of LAD, to propose a diagnostic algorithm and provide management guidelines based primarily on experts' opinion because of the lack of large methodologically sound clinical studies.

METHODS

These guidelines were initiated by the European Academy of Dermatology and Venereology (EADV) Task Force Autoimmune Bullous Diseases (AIBD). To achieve a broad consensus for these S2k consensus-based guidelines, a total of 29 experts from different countries, both European and non-European, including dermatologists, paediatric dermatologists and paediatricians were invited. All members of the guidelines committee agreed to develop consensus-based (S2k) guidelines. Prior to a first virtual consensus meeting, each of the invited authors elaborated a section of the present guidelines focusing on a selected topic, based on the relevant literature. All drafts were circulated among members of the writing group, and recommendations were discussed and voted during two hybrid consensus meetings.

RESULTS

The guidelines summarizes evidence-based and expert opinion-based recommendations (S2 level) on the diagnosis and treatment of LAD.

CONCLUSION

These guidelines will support dermatologists to improve their knowledge on the diagnosis and management of LAD.

Management Options for Linear Immunoglobulin A (IgA) Bullous Dermatosis: A Literature Review

Linear immunoglobulin A (IgA) bullous dermatosis (LABD) is an autoimmune condition with various triggers. Because of the lack of randomized controlled trials on LABD treatment, management options are mostly anecdotal. This paper provides a comprehensive review of treatment options from a literature review of reported treatments to arm clinicians with a guideline for the management of LABD in both pediatric and adult patients as well as those recalcitrant to first-line therapy (dapsone and steroids). We additionally illustrate an algorithm to use for the management of LABD to aid clinicians when faced with unique patient circumstances.

Ulcerative colitis complicated with linear immunoglobulin A bullous dermatosis

Linear immunoglobulin A (IgA) bullous dermatosis (LABD) is a rare disorder involving subepidermal blistering characterised by IgA deposition along the basement membrane. The clinical features of LABD are variable but can include bullae, vesicles and erythematous lesions. Histopathology reveals formation of subepidermal bullae and linearly deposition of IgA in the basement membrane of the epidermis. LABD has been reported as a rare complication of ulcerative colitis (UC). We report the case of a young woman with UC complicated by LABD. The latter manifested as vesicles with erythema on almost the entire body. A biopsy of the skin lesions revealed linear IgA deposits in the basement membrane according to a direct immunofluorescence assay. Prednisolone administration resulted in clinical remission of UC but poor improvement of skin lesions. Oral administration of diaminodiphenyl sulfone led to improvement of blisters. Thereafter, abdominal and skin symptoms did not recur and she was discharged from hospital.

Chronic Oral Lesions

Chronic oral mucosal lesions can be associated with several mucocutaneous diseases. This article reviews the autoimmune and immune-mediated, reactive, genetic, and infectious diseases that may present with chronic oral and/or cutaneous manifestations and provides a rational approach to diagnosis and management.

Linear IgA bullous dermatosis associated with ulcerative colitis: A case report and literature review

We report the case of a 59-year-old Japanese woman who developed linear IgA bullous dermatosis during treatment for ulcerative colitis that manifested as pruritic vesicles with erythema on the trunk and scalp. Histopathological examination revealed subepidermal bulla with neutrophil and eosinophil infiltration in the upper dermis. Direct immunofluorescence revealed linear IgA deposits at the basement membrane zone, and indirect immunofluorescence using split skin revealed IgA reaction to the epidermal side (lamina lucida type). We reviewed 33 reported cases of linear IgA bullous dermatosis associated with ulcerative colitis and found that ulcerative colitis preceded the onset of linear IgA bullous dermatosis in 94% of the patients and that IgA-positive patients in split skin indirect immunofluorescence all showed the lamina lucida type, indicating that target antigens for serum IgA antibodies may reside in the lamina lucida. Regarding the pathogenetic association of ulcerative colitis and linear IgA bullous dermatosis, intestinal inflammation may induce the exposure and presentation of intestinal antigens that are cross-reactive to cutaneous antigens, stimulating autoimmune response to antigens of cutaneous basement membrane zones.

Linear IgA Bullous Dermatosis Preceding the Diagnosis of Primary Sclerosing Cholangitis and Ulcerative Colitis: A Case Report

Linear IgA bullous dermatosis (LABD) is a rare autoimmune blistering disorder seen in the pediatric and adult populations that is often linked to a medication, infection, or underlying gastrointestinal, hepatobiliary, or autoimmune disease. In this study, we describe the case of a 23-year-old white man whose presentation and diagnosis of LABD ultimately led to the discovery of underlying primary sclerosing cholangitis (PSC) and ulcerative colitis (UC). His dermatitis resolved with topical steroids and dapsone, and he is undergoing systemic treatment for his UC and PSC. This exceptional case further validates the association between LABD with UC, strengthens that with PSC, and underscores the importance of alerting clinicians to consider conducting a systemic workup in addition to thorough medication history on making the diagnosis of LABD.

Proteases in Pemphigoid Diseases

Pemphigoid diseases are a subgroup of autoimmune skin diseases characterized by widespread tense blisters. Standard of care typically involves immunosuppressive treatments, which may be insufficient and are often associated with significant adverse events. As such, a deeper understanding of the pathomechanism(s) of pemphigoid diseases is necessary in order to identify improved therapeutic approaches. A major initiator of pemphigoid diseases is the accumulation of autoantibodies against proteins at the dermal-epidermal junction (DEJ), followed by protease activation at the lesion. The contribution of proteases to pemphigoid disease pathogenesis has been investigated using a combination of in vitro and in vivo models. These studies suggest proteolytic degradation of anchoring proteins proximal to the DEJ is crucial for dermal-epidermal separation and blister formation. In addition, proteases can also augment inflammation, expose autoantigenic cryptic epitopes, and/or provoke autoantigen spreading, which are all important in pemphigoid disease pathology. The present review summarizes and critically evaluates the current understanding with respect to the role of proteases in pemphigoid diseases.

Consensus on the treatment of autoimmune bullous dermatoses: dermatitis herpetiformis and linear IgA bullous dermatosis - Brazilian Society of Dermatology

Dermatitis herpetiformis and linear IgA bullous dermatosis are autoimmune diseases that present with pruritic urticarial papules and plaques, with formation of vesicles and blisters of subepidermal location, mediated by IgA antibodies. Mucosal lesions are present only in linear IgA bullous dermatosis. The elaboration of this consensus consisted of a brief presentation of the different aspects of these dermatoses and, above all, of an updated literature review on the various therapeutic options that were discussed and compared with the authors' experience, aiming at the treatment orientation of these diseases in Brazil. Dermatitis herpetiformis is a cutaneous manifestation of celiac disease, and can be controlled with a gluten-free diet and dapsone. On the other hand, linear IgA bullous dermatosis arises spontaneously or is triggered by drugs, and can be controlled with dapsone, but often requires the association of systemic corticosteroids and eventually immunosuppressants.

AUTOIMMUNE BULLOUS DERMATOSES. DIFFERENTIAL DIAGNOSIS

The review presents modern ideas concerning autoimmune bullous dermatoses (pemphigoid group): Duhring disease, bullous pemphigoid, cicatrizing pemphigus, pemphigoid gestationis, linear IgA bullous dermatosis and acquired bullous epidermolysis. Pathogenesis, clinical manifestations and modern methods of disease diagnostics are reported. Particular attention is paid to the diagnosis of acquired bullous epidermolysis, in which the leading role belongs to the reaction of immunofluorescence. The pathogenetic similarity between bullous pemphigoid, linear IgA dermatosis, cicatrizing pemphigoid and pemphigoid gestationis is shown, which allows us to regard them as a variety of a single pathological process.

Bullous, pseudobullous, & pustular dermatoses

Several dermatoses are typified by the formation of spaces (blisters; bullae) within or beneath the epidermis. These may be acellular or filled with particular species of inflammatory cells. Etiological categories include infectious, immune-mediated, genetic, drug-related, and idiopathic lesions. Examples of such disorders include impetigo, Herpes virus infections, pemphigus, bullous pemphigoid and pemphigoid gestationis, epidermolysis bullosa acquisita, IgA-related dermatoses, inherited epidermolysis bullosa variants, Hailey-Hailey disease, and porphyria cutanea tarda. Other conditions manifest microscopic acantholysis within the surface epithelium but are not associated with clinical bullae, such as Darier disease and Grover disease. Finally, both infectious and non-infectious causes exist for the development of neutrophilic pustules in the epidermis, as seen in pustular psoriasis, Sneddon-Wilkinson disease (subcorneal pustular dermatosis), and acute generalized exanthematous pustulosis. This review considers the clinical and histological features of all of these diseases.

Retrospective Study on Autoimmune Blistering Disease in Paediatric Patients

BACKGROUND

Autoimmune blistering diseases (AIBDs) are rare in children and their prevalence in Singapore is unclear. We aimed to investigate the clinical and immunopathologic characteristics of children diagnosed with AIBDs in Singapore.

MATERIALS AND METHODS

The clinical and histology databases at the National Skin Centre in Singapore were searched to identify patients younger than 18 years old diagnosed with an AIBD from January 1, 1998, through December 31, 2012. Patient demographic characteristics, presentation, triggers, investigations, treatments, and disease course were analyzed.

RESULTS

Twelve patients with AIBDs were identified; five (41.7%) had linear immunoglobulin A disease (LAD); two (16.7%) each had pemphigus vulgaris (PV), bullous pemphigoid, and bullous systemic lupus erythematosus; and one (8.3%) had pemphigus foliaceus. Four (33.3%) were female and eight (66.7%) male. The mean age of onset was 8.7 years (range 2-17 years). Most patients were treated with steroids and adjuvant immunosuppressants. Intravenous rituximab was used effectively in a patient with recalcitrant PV. The mean follow-up was 2.35 years (range 0.17-7.33 years). As of the last follow-up, four (33.3%) patients were in complete remission off therapy, two (16.7%) were in complete remission on therapy, four (33.3%) were in partial remission on therapy, and two (16.7%) were lost to follow-up.

CONCLUSION

Consistent with the existing literature, our study shows that LAD is the most common cause of AIBDs in children. Although common in the West, dermatitis herpetiformis was not identified in the current study. Intravenous rituximab may be considered in recalcitrant childhood PV, but vigilant monitoring for side effects is crucial. Immunohistopathologic evaluation is important and repeat biopsies may be of value in patients with atypical disease courses.