Allergic diseases are considered to be prototypes of examples of diseases determined by gene vs. cell interactions environment. Key risk factors include smoking, allergen exposure levels, ozone, diesel exhaust particles, SO2 and NO2.
In addition, viruses play an important role in the exacerbation or development of the disease, especially in the case of asthma. Bacterial superinfections, especially in endotoxin-positive strains of Staphylococcus aureus and other microbes, contribute significantly to the pathophysiology of atopic dermatitis and other allergic diseases.