International Journal of Research in Medical Sciences | June 2016 | Vol 4 | Issue 6 Page 1915 International Journal of Research in Medical Sciences Bai S et al. Int J Res Med Sci. 2016 Jun;4(6):1915-1920 www.msjonline.org pISSN 2320-6071 | eISSN 2320-6012 Research Article Histopathologic diagnostic parameters of psoriasis; a clinicopathological study Saranya Bai*, Sowmya Srinivasan INTRODUCTION Psoriasis is a chronic recurrent papulosquamous disease characterized by epidermal hyperplasia. Clinically the presence of well-defined silvery white scales is characteristic of psoriasis. These scales reveal underlying smooth red membrane with bleeding points on removal of suprapaillary epithelium which is called Auspitz sign. 1 There is world wide variation in prevalence of psoriasis. Psoriasis shows a bimodal age of onset with male predominance. It is an immune mediated disorder with the underlying pathophysiology involving T cells and their interactions with dendritic cells and cells involved in keratin production. 2,3 This disease is characterized by chronic, recurrent exacerbations and remissions that are emotionally and physically debilitating. Long term of psoriasis may cause psoriatic arthritis and risk for co-morbidities. 4 The cardinal histopathological features of psoriasis are a combination of the following: acanthosis, mounds of parakeratosis in an orthokeratotic cornified layer, supra papillary thinning, papillomatosis, inter cellular edema, scattered mitosis of basal and prickle cells and ABSTRACT Background: Psoriasis is a common inflammatory skin disorder comprised of varied histo-morphological features involving both epidermis and dermis. Further, there are psoriasiform lesions which simulate psoriasis. Hence it is mandatory to recognise psoriasis based on histopathological parameters to aid the treatment protocol. Methods: Sixty cases of histopathologically confirmed psoriasis vulgaris and pustular psoriasis excluding psoriasiform dermatitis, reported in the Department of Pathology, over a period of 6 years were analysed. The sections were stained with hematoxylin and eosin stains and analyzed for various morphological parameters. Results: Out of 60 cases 88.33% were psoriasis vulgaris and 11.67% were pustular psoriasis. Age incidence was high in second and fourth decades with male predominance. The commonly involved sites were upper and lower extremities. Significant histopathological parameters were parakeratosis (100%), hyperkeratosis (100%), spongiosis (91.67%), and papillomatosis (73.33%), either hypogranulosis (55%) or agranulosis (45%), and dilated and tortuous capillaries (88.33%, 43.33% respectively) in the dermis. Conclusions: Histopathological correlation is still the gold standard tool for the diagnosis of psoriasis. In the absence of well-formed Munro microabscess and pustules of Kogoj, other epidermal features like parakeratosis, hyperkeratosis, spongiosis, papillomatosis and absent or thinned out granular layer as well as dilated and tortuous capillaries in the dermis can be considered as confirmatory evidence of psoriasis. The reduction or complete absence of granular layer was characteristic of psoriasis and reflected the pathogenesis of defective keratinocyte proliferation. Keywords: Psoriasis vulgaris, Agranulosis, Parakeratosis Department of Pathology, Sri Manakula Vinayagar Medical College and Hospital, Puducherry, Tamil Nadu, India Received: 11 March 2016 Accepted: 22 April 2016 *Correspondence: Dr. Saranya Bai, E-mail: ever8472@gmail.com Copyright: © the author(s), publisher and licensee Medip Academy. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. DOI: http://dx.doi.org/10.18203/2320-6012.ijrms20161733