An allergy starts when the immune system mistakes a substance that's usually harmless for a dangerous invader. The immune system then makes antibodies that stay on the alert for that specific allergen. This leads to an allergic reaction when the person is exposed to the allergen again.
Allergic reactions can happen at any time, but they are often triggered by seasonal allergens such as pollen, mold, or dust mites.
For example, ragweed season, which is a common cause of seasonal allergies, typically starts around August and can last for several weeks.
Here are some key points to consider:
- Allergic reactions can happen immediately after exposure to an allergen or delayed for several hours.
- Allergy symptoms can vary depending on the person and the allergen.
- Some people are genetically predisposed to allergies.
- Environmental factors can also play a role in the development of allergies.
