Psoriasis exacerbated by interferon-alpha in a patient with chronic myeloid leukemia.

Interferon-alpha can exacerbate existing psoriasis and induce de novo psoriasis and psoriatic arthritits. The exact underlying mechanism is not very well understood. It is not a contraindication to treat patients with pre-existing psoriasis with interferon-alpha. In these patients interferon-alpha should be used with care and only if the potential benefits justify the potential risk. Control of psoriasis prior to initiation of interferon-alpha and simultaneous antipsoriatic therapy while on interferon-alpha are essential. We would like to report a 61-year-old male patient with stable psoriasis for over 20 years, who experienced exacerbation of his psoriasis after receiving interferon-alpha for chronic myeloid leukemia. The association between the interferon-alpha therapy and the exacerbation of his psoriasis was only recognized on rechallenge at the stage he was referred to our department.