Allergic march describes the common order in which atopy presents

Atopic eczema —> food allergy —> asthma —> allergic rhinitis

Up to 90% of people with allergies are sensitised to multiple allergens, on average at least three.

Reducing exposure to background allergens (e.g. dog dander, moulds) should lessen the likelihood of extrinsic triggers (seasonal pollens or viral LRTI) to cause symptoms as the person’s immune system is further from reaching the allergen load that results in an allergic reaction.