Clinicohistopathologic study of lichenoid interface dermatitis

Abstract

Background: Interface dermatitis (IFD)/lichenoid tissue reactions are among the most frequently presenting disorders in dermatology, which in common have a constellation of histopathological features but varied clinical presentation. Aim: Clinicopathologic correlation and determination of histomorphologic changes associated with various lichenoid IFD of the skin. Materials and Methods: This was a prospective study with purposive sampling of patients reporting to the outpatient department of dermatology, venerology, and leprosy of our hospital from January 2017 to July 2018. Skin biopsies of 150 patients of either sex diagnosed provisionally as one of the lichenoid IFD on clinical grounds were studied. Clinicohistopathologic correlation was done. Results: We encountered 58 cases of classic lichen planus, seven variants of lichen planus (hypertrophic lichen planus, ashy dermatosis, lichen planus pigmentosus, actinic lichen planus, lichen planopilaris, lichen nitidus, and lichen striatus), and 16 cases of lichenoid eruptions. About 82.6% of the cases were concordant histopathologically. The peak incidence was in 20–40 years of age with an equal predilection for males and females. A majority of the lesions were multiple, pruritic, papules, and plaques involving the limbs. Histopathologically, the most consistent findings were basal cell vacuolar degeneration followed by melanin incontinence. Conclusion: Lichenoid IFDs are exclusive clinicopathological entities with several variants. Subtle features noted on histopathology help in differentiating these lesions. Understanding and interpreting these subtle changes aids in better clinical management of the patient.