Seasonal Allergies: At a Glance
Seasonal allergies, also called hay fever, result from exposure to airborne substances (such as pollens) that appear only during certain times of the year.
The term hay fever is somewhat misleading because symptoms do not occur only in the summer when hay is traditionally gathered and never include fever. Hay fever is usually a reaction to pollens and grasses. The pollens that cause hay fever vary by season, and different parts of the country have very different pollen seasons.
People may react to one or more pollens, so their pollen allergy season may be from early spring to late fall. Seasonal allergy is also caused by mold spores, which can be airborne for long periods of time during the spring, summer, and fall.
Normally, the immune system defends the body against foreign substances (called antigens). However, in susceptible people, the immune system can overreact when exposed to certain substances (allergens) in the environment, which are harmless in most people. For more information about allergies, see Allergic Reactions.
For a full discussion, see Seasonal Allergies.
The symptoms of allergies can be very similar to those of the common cold, but there are some differences.
What’s the Same?
Both allergies and colds cause
Seasonal allergies cause the following, and a cold does not:
Colds may cause the following, and allergies do not:
Several strategies can help:
Avoiding the substance that triggers the allergy prevents symptoms but is often not possible.
Using nasal corticosteroid sprays decreases nasal inflammation. These sprays are relatively safe for long-term use.
Taking antihistamines helps prevent the allergic reaction and thus symptoms.
Getting allergy shots (desensitization) helps build long-term tolerance to specific environmental triggers, but the shots may take months or years to become fully effective.