TNF alfa blockers are widely used for treatment of severe psoriasis. These biologics are well-tolerated with few side effects.||Unfortunately not all patients respond adequately to treatment with tnf alfa blockers. Some do not respond at all while others respond initially but gradually lose effect despite increased dose and more frequent administration.||The cause of treatment failure is largely unknown and it may be production of tnf-alfa neutralizing antibodies. This has been demonstrated in patients with rheumatoid arthritis and inflammatory bowel disease who lost response after treatment with tnf-alfa blockers.