What things in common does allergies and asthma have?

"atopy" Both asthma and allergy (such as allergic rhinitis) are potential manifestations of what is known as "atopy." atopy means that someone has an underlying allergic inclination due to allergic antibody that can manifest as eczema, nasal or ocular allergies, food allergies, or asthma. About 60% or so of asthma is allergic or atopic asthma, but about 40% of asthma is not caused by allergy.
Etiology... Both allergies and asthma can have the same etiology. That is, both allergy symptoms and asthma symptoms can be caused by the same allergic triggers in a susceptible person.