Giant Verrucous Psoriatic Plaque encircled by Porokeratosis: An Enigmatic Histopathological Association

Porokeratosis is an inherited, clonal disorder of epidermal keratinization classically characterized by development of single or multiple annular lesions with raised, sharply marginated, keratotic ridge and central atrophy. This clinical presentation may vary with different types of porokeratosis but histopathologically unified by the consistent finding of ‘cornoid lamella’. Porokeratosis may develop sporadically due to genetic predisposition or as a result of locally induced immunosuppression. In medical literature, to the best of our knowledge, there are very few reported cases in which lesions of psoriasis were also having cornoid lamella at the margin of the psoriatic lesion and it has recently been described as ‘‘psoriasis encircled by porokeratosis.’’ Here we document a rare case of giant verrucous psoriatic plaque with porokeratosis at the margin in a 25 years old male who was not immunosuppressed and has not received any immunosuppressive treatment such as steroids or photochemotherapy.