Unilateral Psoriasis on the Left Leg and Poliomyelitis of the Right Leg: A Case Report and Review of the Etiology.

Psoriasis is a common immune-mediated, inflammatory skin disease. However, unilateral psoriasis is rare and few cases have been reported. A 59-year-old male with a polio-affected right leg presented with exfoliative skin on the left leg for three months. He had been treated under the diagnosis of contact dermatitis with secondary infection. After the exfoliative skin lesions improved, psoriatic papules were noted, which was ultimately diagnosed as psoriasis and successfully treated with topical steroid and vitamin D agents. We propose that the Koebner phenomenon has acted as the triggering and aggravating factor of unilateral psoriasis in this patient.