The Köbner Phenomenon and Psoriatic Arthritis

Psoriatic arthritis (PsA) affects a large percentage of patients with psoriasis. Similar to the cutaneous disease of psoriasis, PsA displays an isomorphic response (ie, the propensity to develop at traumatized sites). In some patients, traumatized joints that subsequently develop PsA are the initial manifestation of psoriasis, preceding the skin disease by months to years. Dermatologists should screen patients with psoriasis for accompanying PsA and consider recently traumatized joints that remain arthritic to be a component of this disease.