etiology The pathogenesis of asthma is complicated and is affected by genetics and the environment. It is a multigene disoder and closely related to atopy. Most patients have prior history of eczema, allergic rhinitis, food or drug allergy, and quite a few patients have family history. The formation and attack of asthma is also a consequence of the function of multiple environmental factors such as inhalation of allergens respiratory tract infection, and coldnessetiology The pathogenesis of asthma is complicated and is affected by genetics and the environment. It is a multigene disoder and closely related to atopy. Most patients have prior history of eczema, allergic rhinitis, food or drug allergy, and quite a few patients have family history. The formation and attack of asthma is also a consequence of the function of multiple environmental factors such as inhalation of allergens, respiratory tract infection, and coldness