Clinicohistological correlation of psoriasis and immunohistochemical expression of Ki 67

Skin is considered as the largest organ of the body. Psoriasis is a chronic papillosquamous disorder of skin affecting 1-2% of population in all geographic areas.(4) There is a seven fold increase in the field of epidermal cell proliferation. Psoriasis is a disease characterized by chronic, recurrent exacerbation and remission that are emotionally and physically debilitating, therefore accurate diagnosis by histopathologist is essential. Psoriasis is enormously variable in its duration and extent. There are several morphological variants. Psoriasis has different clinical variants which mimics diverse dermatological condition. Histopathology is required to confirm the diagnosis and subtype the lesion. Recent advances in cell kinetics, immunology and molecular biology had increased our understanding of the etiopathogenesis of keratinocyte proliferation in this disorder. Ki 67 is a proliferative marker which is increased in keratinocytes of psoriatic patients. In this study we have analysed various patterns of psoriasis in adults and paediatric age group with clinicohistopathological correlation. Immunohistochemical staining with Ki 67 was also done to study the proliferative index in psoriatic skin epidermis in both adult and paediatric age group.