Clinical, demographic and immunopathological spectrum of subepidermal autoimmune bullous diseases at a tertiary center: A 1-year audit

Background: The subepidermal autoimmune bullous diseases are a subset of immunobullous diseases encountered less frequently in the Indian population. There is a paucity of data on the prevalence, demographic and clinicopathological spectrum of various subepidermal autoimmune bullous diseases from India. Aim: To determine the demographic and clinicopathological profile of subepidermal autoimmune bullous diseases in Indian patients, presenting to the Immunobullous Disease Clinic of Postgraduate Institute of Medical Education and Research, Chandigarh. Methods: Patients seen from November 2013 to November 2014 who fulfilled the preset diagnostic criteria of subepidermal autoimmune bullous diseases were identified from case records. Data regarding demographic characteristics, clinical profile, immunopathological findings and treatment were collected from the predesigned proforma. Results: Of 268 cases of autoimmune bullous diseases registered, 50 (18.7%) were subepidermal autoimmune bullous diseases. Bullous pemphigoid was most frequently seen in 20 (40%) cases, followed by dermatitis herpetiformis in 14 (28%), mucous membrane pemphigoid in 6 (12%), chronic bullous dermatosis of childhood /linear immunoglobulin A bullous dermatosis in 5 (10%), lichen planus pemphigoides in 3 (6%), pemphigoid gestationis and epidermolysis bullosa acquisita in 1 (2%) case each. None of the patients had bullous systemic lupus erythematosus. Limitations: We could not perform direct and indirect immunofluorescence using salt-split skin as a substrate and immunoblotting due to non-availability of these facilities. Therefore, misclassification of subepidermal autoimmune bullous diseases in some cases cannot be confidently excluded. Conclusion: Subepidermal autoimmune bullous diseases are not uncommon in Indian patients. Bullous pemphigoid contributes maximally to the burden of subepidermal autoimmune bullous diseases in India, similar to that in the West, although the proportion is lower and disease onset is earlier. Dermatitis herpetiformis was observed to have a higher prevalence in our population, compared to that in the West and the Far East countries. The prevalence of other subepidermal autoimmune bullous diseases is relatively low. Detailed immunofluorescence and immunoblotting studies on larger patient numbers would help better characterize the pattern of subepidermal autoimmune bullous diseases and their features in Indian patients.