Abstract: The present invention relates to methods of treating patients suffering from itching and puritis mediated by cutaneous lymphocyte antigen positive T cell. In particular, diseases or disorders including contact dermatitis, drug induced delayed type cutaneous allergic reactions, toxic epidermal necrolysis, cutaneous T cell lymphoma, bullous pemphigoid, alopecia aereata, vitiligo, acne rosacea, prurigo nodularis, and herpes simplex virus, or combination thereof will benefit from the administration of an IL-31 antagonist. The invention also includes methods of predicting a therapeutically responsive patient population.