Allergies can be triggered by a wide range of substances. Common causes include:
* Environmental allergens: Pollens from grasses and trees, dust mites, mold spores.
* Animal-related allergens: Pet dander and fur.
* Food allergens: Various food items such as milk, eggs, soy, seafood, fruits, and nuts.
* Insect venom: Stings from insects like bees.
* Medications: Certain pharmaceutical drugs.
* Contact allergens: Substances like chemical resins, latex/rubber, nickel, often found in jewelry (e.g., necklaces, earrings) and other products.