The atopic march was described more than 20 years ago on the basis of initial observations, and it is now seen in prospective studies. The concept has evolved and is now considered to be the progression of atopic dermatitis to other atopic conditions, including asthma, allergic rhinitis, food allergy, and eosinophilic esophagitis in a nonlinear fashion. The progression can include some or all of the aforementioned atopic conditions. The pathogenesis is part of the classic type 2 inflammatory process involving IL-4, IL-5, and IL-13 preceded by induction of the alarmins (thymic stromal lymphopoietin, IL-33, and IL-25), leading to production of IgE in a genetically predisposed individual. The development of new biologics that interact with T2 pathway represent possible ways to prevent or modify the atopic march.