Biologic therapy in atopic disease is the first step toward targeted precision medicine. In this chapter, we highlight recent data on biologic agents that are currently approved by the U.S. Food and Drug Administration (FDA), or are likely to be approved, for asthma, urticaria, atopic dermatitis, and nasal polyps. We discuss T2 high inflammation as the cornerstone of allergic disease. Understanding the underlining inflammatory process is key for stratification of appropriate use of biologic agents at bedside. Furthermore, we discuss currently available clinical biomarkers.