Methods for treating medical conditions induced by interleukin-4 involve administering an IL-4 antagonist to a patient afflicted with such a condition. Suitable IL-4 antagonists include, but are not limited to, IL-4 receptors (such as a soluble human IL-4 receptor), antibodies that bind IL-4, antibodies that bind IL-4R, IL-4 muteins that bind to IL-4R but do not induce a biological response, molecules that inhibit IL-4-induced signal transduction, and other compounds that inhibit a biological effect that results from the binding of IL-4 to a cell surface IL-4R. Particular antibodies provided herein include human monoclonal antibodies generated by procedures involving immunization of transgenic mice. Such human antibodies may be raised against human IL-4 receptor. Certain of the antibodies inhibit both IL-4-induced and IL-13-induced biological activities.