Lichenoid tissue reactions (LTRs) represent a diverse group of conditions similar to lichen planus clinically and histopathologically. Lichen planus is a common lesion that may involve the skin, mucus membranes, hair follicles and nails. A retrospective study of two years was conducted on skin biopsies with pathological diagnosis of lichen planus and other dermatological lesions resembling lichen planus clinically. The clinical findings and pathological parameters were noted for analysis and correlation. Histopathological parameters such as epidermal changes, changes at the dermoepidermal junction, dermal changes and dermal reaction pattern were studied. The lesions were divided into three distinct and well defined categories- Lichenoid dermatitis, Interface dermatitis and miscellaneous category. Lichen planus was the classical prototype of lichenoid dermatitis. Erythema multiforme was the classical prototype of interface dermatitis. The criteria used to differentiate and categorize the group of cutaneous lesions help in making a more definitive diagnosis and narrow the differential diagnosis amongst this vast group of chronic superficial dermatoses. Therefore an emphasis on the clinical correlation is crucial for the precise diagnosis of interface dermatitis and histopathological examination remains an indispensable tool that helps in rendering an accurate diagnosis.
