Direct Immunofluorescence Studies in Lichen Planus.

Objective Lichen planus is a common, usually intensely pruritic, symmetrical, papulosquamous dermatosis. Direct immunofluorescence studies in patients with lichen planus shows deposition of multiple immunoglobulins and fibrin at the dermoepidermal junction and in the colloid bodies. Material and method Histopathological features were analysed in 100 cases of lichen planus which were sent for routine histology. Direct immunofluorescence studies were done in 22 out of the 100 cases and the features were analysed. Clinical data was recorded from patient files. Results Positive direct immunofluorescence was seen in 78.5% of the cases. Deposits at the dermoepidermal junction and colloid bodies were detected in 88% and 40% of the cases respectively. IgG, IgM and C3 deposition was seen in 88%, 70% and 24% respectively. IgA was negative in all the cases. Conclusion The linear and shaggy deposition of immunoreactants in a discontinuous form along the dermoepidermal junction and in the colloid bodies were indicators in support of lichen planus along with the characteristic histopathological findings. In lupus erythematosus, linear and granular deposition of immunoglobulins in a continuous form is found along the dermoepidermal junction. Direct immunofluorescence studies are of immense help in disease differentiation in cases of interface dermatitis with no specific histological or clinical characteristics and in cases with ambiguous features.