Common allergens are as follows: 1. Inhaled allergens: such as pollen, willow wool, dust, mites, animal dander, oil fumes, paint, car exhaust, gas, cigarettes, etc. 2, ingested allergens: such as milk, eggs, fish and shrimp, beef and mutton, seafood, animal fat, allogeneic proteins, alcohol, drugs, antibacterial agents, anti-inflammatory drugs, fragrance oil, fragrance, onion, ginger, garlic, and some vegetables, fruits, etc. 3, contact allergens: such as cold air, hot air, ultraviolet light, radiation, cosmetics, shampoo, detergent, hair dye, soap, chemical fiber products, plastic, metal jewelry (watches, necklaces, rings, earrings), bacteria, mold, viruses, parasites, etc. 4.Injectable allergens: such as penicillin, streptomycin, heterologous serum, etc. 5, own tissue antigens: mental tension, work stress, microbial infection, ionizing radiation, burns and other biological, physical and chemical factors that change the structure or composition of their own tissue antigens, as well as their own hidden antigens released due to trauma or infection, can also become allergens.