Allergic rhinitis allergic rhinitis also have asthma, allergic conjunctivitis, or atopic dermatitis. Allergic rhinitis is typically triggered by environmental allergens such as pollen, pet hair, dust, or mold. Inherited genetics and environmental exposures contribute to the development of allergies. Growing up on a farm and having multiple siblings decreases the risk. The underlying mechanism involves IgE antibodies attaching to the allergen and causing the release of inflammatory chemicals such as histamine from mast cells. Diagnosis is usually based on a medical history in combination with a skin prick test or blood tests for allergen-specific IgE antibodies. These tests, however, are sometimes falsely
William P. Dunbar theories about "hay fever" that were current in the late 1800s. Dunbar determined that it was the dried cat saliva on cat hair that caused the allergic reaction. With regard to grass pollen, Dunbar identified the albumin fraction as the active toxin, discovered changes in the blood that accompanied exposure to the pollen, and was able to grade individual's relative susceptibility to each type of pollen. Much of his work on allergies is summed up in his 1913 publication "The present state of knowledge of hay fever". William P. Dunbar William Philipps Dunbar (1863 in Minnesota – 1922) was an