Allergies occur when your immune system reacts to a foreign substance — such as pollen, bee venom or pet dander — or a food that doesn’t cause a reaction in most people. That substance is referred to as an allergen
The allergen stimulates immune system cells to release certain chemicals, such as histamine, which then lead to allergy symptoms.
Some of the symptoms of an allergic reaction include:
• Itchy, watery eyes.
• Itchy nose.
• Runny nose.
• Hives (a rash with raised red patches)
• Stomach cramps.