A Histopathological Study: Ñ-Sign, The Visual Clues In The Diagnosis Of Psoriasis In A Tertiary Care Centre - An Observational Study

Abstract

Introduction: Psoriasis is a common chronic inflammatory skin disease that affects >60 million worldwide. The “ñ-sign” may be a visual clue for the histopathological diagnosis of psoriasis which aids in giving a definitive diagnosis in comparison with other inflammatory skin disorders.

Objectives:  To determine the visual clues (ñ-sign) in the histopathological diagnosis of psoriasis and compare the histopathological findings between papulosquamous skin disorders and psoriasis.

Methodology: A retrospective observational study was done on all skin punch biopsy samples received as papulosquamous disorders. The ñ-sign was evaluated in the test group in comparison with the control group.

Results: 36 cases were clinically diagnosed as psoriasis while the rest of them (24) were diagnosed as papulosquamous disorders (n=60). Of the 36 cases of psoriasis, 33 were diagnosed as psoriasis on histopathology. The ñ-sign was present in 31 (93.9%) cases and was absent in 2 cases (6.1%) of test group (P <0.001). The combination of ñ sign with hypogranulosis was present in 6 cases (18.2%), ñ-sign with neutrophil infiltration was present in 7 cases (21.2%) and ñ-sign with hypogranulosis and neutrophilic infiltrate was present in 14 cases (42.4%) of test group respectively. Only ñ-sign was present in 4 cases (12.1%) of the test group. Sensitivity and specificity of ñ-sign in the test group were 93.9% and 100% respectively.

Conclusion: These visual clues (ñ-sign) help the pathologists and dermatologists in aiding a definitive diagnosis of psoriasis in early diagnosis and treatment of the same as they share similar features with inflammatory skin disorders.