Evaluation of salt split technique of immunofluorescence in bullous pemphigoid

Recent studies suggest that salt split skin is a more sensitive substrate than intact skin for immunofluorescence diagnosis of bullous pemphigoid. We undertook this study to define the role of salt split technique of immunofluorescence findings in 32 clinical and histopathology confirmed cases of bullous pemphigoid. Both direct and indirect immunofluorescences were performed using normal and split skin. Direct immunofluorescence positivity of 100% was noted with both routine and salt split method. Additional immunoreactant deposition was noted with direct method on split skin in 5 cases. Patterns of fluorescence in the latter were roof (40.60%), floor (9.4%) and combined roof and floor (50%). On indirect immunofluorescence, positivity was almost doubled with salt split technique ( 68%) as compared to routine method (36%). Thus, salt split technique was equivalent to routine on direct method in positivity with additional immunoreactant deposits noted in some and had double the sensitivity of the indirect method in detecting immunofluorescence in bullous pemphigoid.