Pityriasis rosea in a patient with Behçet's disease treated with interferon alpha 2A.

Interferons have been used for the treatment of many diseases because of their immunomodulatory, antiviral, antitumoral, and antiproliferative effects. Systemic interferon alpha 2a (IFN-alpha 2a) is also efficacious in the management of Behçet's disease (BD). Many adverse cutaneous reactions related to IFN-alpha have been reported. In the light of the current literature, we report here the first case of Pityriasis rosea (PR) that developed while receiving IFN-alpha 2a for BD. However, since this is the first report on this association, further observations are needed to determine their clinical relevance.