The skin is red, swollen and hard after being bitten by insects is the occurrence of insect bite dermatitis, it is recommended to wash the local area with water, and use drugs such as Dinaid cream and loratadine for anti-inflammatory, itch-relieving and anti-allergic treatment under the guidance of a doctor. 1. Local treatment: After being bitten by bugs, you can use flowing water to rinse the skin to reduce the retention of toxins and alleviate the symptoms of itching, redness, swelling and hardness of the skin; after being stung by a bee, you need to pull out the stinger immediately, squeeze out the venom and then use water to rinse it; after being bitten by ticks, you can’t forcibly pull it out so as not to break off the mouthparts in the skin, and it needs to be taken out by a doctor. 2. Drug treatment: under the guidance of the doctor, you can use Denadyl cream, mometasone furoate cream and other glucocorticoid drugs to apply locally, in order to achieve the effect of rapid itching and anti-allergy; when itching symptoms are obvious, you can take antihistamines such as loratadine and cetirizine orally; when accompanied by infections, you can use mupirocin ointment and other drugs for anti-infective treatment. It is recommended that patients with red, swollen and hardened skin after being bitten by insects be treated with medication under the guidance of a doctor, and avoid using medication privately to avoid delaying the condition.