For some people, allergies and asthma may occur together, which is known as allergic asthma, or allergy-induced asthma.
An allergic reaction occurs when antibodies in the immune system mistakenly identify a harmless substance, such as tree pollen, dust mites or pet dander, as an invader. To protect the body, antibodies bind to the allergen. The chemicals released by the immune system to fight the allergen lead to allergy symptoms, such as congestion, runny nose and itchy eyes.
A variety of treatments can help people with persistent nasal allergies find some relief. Eye drops, saline sprays and oral antihistamines are available over the counter and can treat mild symptoms. A steroid nasal spray may also be recommended for moderate allergies.