Allergies leave black marks mostly due to inflammation resulting in hyperpigmentation, generally acute allergies leave hyperpigmentation for temporary, can be self-relieved over time, if the chronic allergies, hyperpigmentation is more stubborn, long can form local mossy lesions, need to be treated according to the cause and symptoms. 1, physical therapy: local hyperpigmentation pay attention to sun protection, apply sunscreen or wear sunscreen clothing. Under the guidance of a doctor, topical moisturizer, moisturizing spray, etc., nourish the skin to lighten hyperpigmentation; 2, drug treatment: under the guidance of a doctor, topical vitamin A acid ointment, adapalene gel, etc., supplemented by liver function and blood lipids without abnormalities can take vitamin C, isotretinoin soft capsules and vitamin capsules to lighten hyperpigmentation; 3, medical aesthetic treatment: stubborn hyperpigmentation, through the hydrophobic needle, photorejuvenation, beauty Laser, fruit acid peeling or liquid nitrogen freezing treatment to remove pigmentation, so as to achieve the effect of lightening black marks. The general liquid nitrogen freezing treatment can make the pigment crust, 7-14 days crust subsides, pigmentation will disappear, the cure rate is high and low cost; 4, diet conditioning: diet light, avoid drinking a lot of alcohol and excessive intake of chili, beef, coffee and other stimulating food, eat more vitamin-rich fruits and vegetables, such as watermelon, oranges, spinach, cabbage, etc., to speed up the lightening of pigmentation.