An allergy is a specific reaction of the body’s immune system to a normally harmless substance, one that does not bother most people. People who have allergies often are sensitive to more than one substance. Types of allergens that cause allergic reactions include:
- Pollens
- House dust mites
- Mold spores
- Food
- Latex rubber
- Insect venom
- Medicines
Courtesy: National Institute of Allergy and Infectious Diseases