A lot, as it turns out. Allergies and asthma often occur together. The same substances that trigger your hay fever symptoms, such as pollen, dust mites and pet. Allergic asthma is asthma caused by an allergic reaction. It's also known as allergy-induced asthma. You may have allergic asthma if you have. Allergic asthma is triggered by inhaled allergens such as dust mites, pet dander, pollen, mold, etc. resulting in asthma symptoms.