There is provided an isolated antibody or antibody fragment that binds to human IL-31, comprising: a) a humanized heavy chain variable domain comprising CDR1, CDR2, and CDR3 consisting of amino acid sequences SEQ ID NO: 1, 2 and 3, respectively; and b) a humanized light chain variable domain comprising CDR1, CDR2, and CDR3 consisting of amino acid sequences of SEQ ID NO: 5, 6 and 7, respectively.