A seasonal allergy is an allergic reaction to a trigger that is typically only present for part of a year, such as spring or fall. This type of allergy refers to a pollen allergy, such as trees, weeds and grasses. Perennial allergies, on the other hand, are usually present year-round, and include allergens such as pet dander and house dust mite. Molds can be a seasonal or perennial allergy trigger.
Symptoms may include allergic rhinitis (hay fever), allergic conjunctivitis (eye allergies) and allergic asthma.
Pollens that are spread by the wind are usually the main cause of seasonal allergies.
Pollen can travel long distances and the levels in the air can vary from day to day. The pollen level can be quite different in various areas of a particular city or area. Levels of pollen tend to be highest from early morning to mid-morning, from 5AM to 10AM.
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