Occurrence of Psoriatic Arthritis during Interferon Beta 1a Treatment for Multiple Sclerosis. Toussirot E, Béreau M, Bossert M, Malkoun I, Lohse A Case Rep Rheumatol. 2014; 2014:949317. Epub 2014 Apr 15. PMID: 24839574. Abstract CommentRecommendBookmarkWatch