Unveiling the invisible: Utility of direct immunofluorescence in non-bullous skin lesions

Histopathology is the cornerstone for diagnosis of dermatological conditions, with developments in immunopathology; direct immunofluorescence is a proven adjunct in bullous and non-bullous disorders. Here we emphasize the role of direct immunofluorescence in non-bullous diseases encountered in clinical practice. This is a descriptive, ambispective study conducted over a period of 3 years, where all clinically observed non-bullous disorders were included. The samples were processed for histopathology and direct immunofluorescence and results observed. The collected data was evaluated and analyzed and the clinical, histopathological and DIF diagnosis were compared across each other. Our cohort consisted of 61 cases of non-bullous lesions, of total 141 skin samples received for direct immunofluorescence. Majority of cases were vasculitis(44%), followed by lichen planus(24%), lupus erythematosus(6%), and psoriasis(5%) among others. An overall good clinic-histological concordance(87%) was noted with positive direct immunofluorescence findings in 68.85% cases. Direct immunofluorescence was crucial in establishing the diagnosis of vasculitis and further categorization into Henoch-Schonlein purpura(IgA vasculitis), diagnosis of case of lichen planus & lupus erythematosus with non-specific histomorphology and in ruling out of dermatitis herpetiformis. Direct immunofluorescence could be crucial in diagnosis of certain non-bullous disorders where; no diagnosis was possible due to nonspecific characteristics. In such cases, direct immunofluorescence is a rapid, efficient and convenient tool in diagnostic dermatology. However, the clinical, histopathological and direct immunofluorescence findings are always to be considered together for a definitive final diagnosis.