An early sign that a child might develop an allergy is if they have eczema, also known as atopic dermatitis, which is a condition that causes a person’s skin to be dry and itchy. In research published in March 2024 and led by Donald Leung at National Jewish Health [and professor of pediatrics at CU School of Medicine], doctors used a special piece of tape to retrieve a skin sample from 2-month-old babies.