Linear IgA dermatosis in association with angioimmunoblastic T-cell lymphoma infiltrating the skin: A case report with literature review

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.

Linear IgA Bullous Dermatosis in Korea Using the Nationwide Health Insurance Database

(1) Background: Linear immunoglobulin A bullous dermatosis (LABD) is a rare autoimmune, subepidermal blistering disease, characterized by linear IgA deposits along the epidermal basement membrane. LABD is idiopathic and is associated with medication and systemic autoimmune diseases. (2) Methods: We investigated the demographic characteristics, disease course, causative agents, and associated diseases in Korean patients with LABD. The Korean Health Insurance Review and Assessment Service database was used to obtain data. We identified 670 LABD cases between 2010 and 2022. (3) Results: The annual incidence of LABD was 1.3 per 100,000 persons, with a higher prevalence in individuals ≥60 years old. The patients were treated with dapsone for 30.7 ± 56.7 days, had 1.3 ± 0.7 hospital visits, and were hospitalized for 19.8 ± 19.7 days. Risk factors, including malignancy, commonly preceded LABD. Antibiotic use, specifically vancomycin and third-generation cephalosporins, was a risk factor. The mean age of LABD diagnosis was 55.9 ± 21.7 years. (4) Conclusion: This is the first published study to assess a nationwide cohort for LABD. The incidence of LABD was higher than that in other studies. Most case reports have linked LABD with the administration of specific antibiotics; however, this study shows there were more associations with other conditions.

A Case of Lamina Lucida-Type Linear IgA Disease Complicated by Colon Polyposis and Rectal Adenocarcinoma

Linear IgA disease (LAD) is a rare autoimmune bullous disease characterized by IgA deposition in the basement membrane zone (BMZ). A 66-year-old male was treated for myelodysplastic syndrome at our hospital for 5 years, during which his condition remained stable. He visited our department because of erythema with itching, which appeared 1 year ago and gradually exacerbated with the development of blisters and erosions. During the first visit, multiple erythemas with erosions and crusts on their periphery were observed on the trunk and lower limbs. Histopathological examination revealed subepidermal blisters with inflammatory cell infiltration, mainly constituting of neutrophils, eosinophils, and lymphocytes. Direct and indirect immunofluorescence showed linear IgA deposits in the BMZ and IgA anti-BMZ antibodies, respectively, while immunoblotting using a concentrated culture supernatant of HaCaT cells detected IgA antibodies reactive to 120-kDa LAD-1. Accordingly, the patient was diagnosed with lamina lucida-type LAD. Subsequent colonoscopy revealed multiple colorectal polyps and rectal adenocarcinoma (Tis, N0, and M0). Multigene panel test showed an ATM variant of unknown significance but did not detect any pathogenic variants associated with intestinal polyposis syndrome. The skin lesions quickly resolved with oral diaphenylsulfone 50 mg/day and resection of the colorectal polyps and adenocarcinoma. To our knowledge, this is the first reported case of LAD associated with multiple colorectal polyps and rectal adenocarcinoma. Additionally, we also analyzed reported cases of LAD associated with malignancy from the literature.

Linear IgA bullous dermatosis in the setting of angioimmunoblastic T-cell lymphoma

We report an 80-year-old male developing linear IgA bullous dermatosis (LAD) in the setting of angioimmunoblastic T-cell lymphoma (AITL). This phenomenon is rare, as only three cases have been described in the literature. The pathophysiologic process can be attributed to dysregulation in somatic hypermutation and the expression of chemokine receptor 5 in AITL, contributing to increased IgA. Immunoglobulin production resulting from clonal plasma cell expansion may be because of the B-cell promotional effect by neoplastic follicular helper T-cells. Beyond providing a pathophysiologic platform for AITL-associated LAD, we also briefly summarized prior cases. This report demonstrates the importance of considering LAD in the differential diagnosis for patients with a bullous eruption in the setting of AITL.

Idiopathic linear IgA bullous dermatosis treated with prednisone

We present a case of a 43-year-old man with a medical history of paroxysmal atrial fibrillation that presented with acute onset generalised vesiculobullous rash of 1-week duration. The rash was initially noticed on his groin and then spread to his hands, feet and mucosal surfaces. Laboratory tests were unremarkable, including an extensive infection aetiology work-up. Punch biopsies were obtained of a fresh lesion and were stained with H&E and sent for direct immunofluorescence. Light microscopy and immunofluorescence study demonstrated a subepidermal blister with predominant neutrophilic infiltrates and a linear band of IgA at the dermoepidermal junction, respectively. The patient was diagnosed with linear IgA bullous dermatosis and was subsequently treated with 0.5 mg/kg of prednisone daily following previous case reports. At 1-week follow-up as an outpatient, the bullae became crusted, and the rash was nearly completely regressed.