By Roberta Attanasio The frequency of allergies in children keeps rising rapidly worldwide, but it’s not clear why. However, it is acknowledged that developing even one type of allergy early in life is almost like turning on a switch—it can start children on a path to more. “The progression of skin allergies to asthma and allergic rhinitis is called the allergic or atopic march. Atopic dermatitis is an itchy, inflammatory skin allergy that, before 1960, affected fewer than 3% of children; by the 2000s it had increased to around 20%. A child with atopic dermatitis is more likely to develop other allergic conditions or symptoms. For example, about 70% of…