Summer is here, and with it the chances of exposure to insects increase dramatically. Every year, thousands of people suffer from insect bites, especially hymenopterous insects, including wasps, hornets, bees and ants, and mosquitoes. After being bitten by insects, most people show a temporary reaction to the bite site, such as mild redness, swelling, and pain. In this case, if the skin is not infected, just rinse with soap and water and use ice to apply a cold compress, and it will usually improve in 30 to 60 minutes. If small local blisters appear, the swelling and pain may last for about 4 hours. Be careful not to break the blisters to avoid secondary infection. Bees often leave their stings in the skin, which must be removed immediately, but be careful not to squeeze the area to avoid spreading the venom. In 7-17% of cases, there will be enlarged erythema and swelling at the site of the sting, which may be larger than 10 cm in diameter and can last for several days. In addition to local skin disinfection and cold compresses, some hormonal ointment can be applied and oral antihistamines such as loratadine and cetirizine can be administered. The same reaction occurs in such patients after being bitten again, and anaphylaxis may even occur in 3-10% of them. Less common allergic reactions to insect bites include serum sickness-like reactions such as urticaria, arthralgia, general malaise, and fever, which occur 7 days after the bite. Such individuals are also at risk for anaphylaxis after a second bite. Other rare reactions include neurological, renal, vascular, and encephalopathy-like reactions, which occur 2 weeks after the bite. Toxic reactions refer to the occurrence of hypotension, cardiovascular insufficiency of blood supply, and possible death in severe cases after being bitten by a group of insects at the same time. Muscle lysis, skin damage, hemolysis, and acute renal failure may also occur. Anaphylaxis is the most severe reaction to insect bite allergy and is most often seen in adults after a bee bite. It may manifest as a rash, bronchospasm, laryngeal edema, hypotension, cardiac arrhythmia, and even cardiac and respiratory arrest. In patients with a history of shock, the same reaction occurs in 60% of adults and 20% of children after another bite. Patients should carry an epinephrine device with them in case of emergency. People who experience rare reactions, toxic reactions and anaphylaxis after insect bites should visit a medical professional for further diagnosis and treatment to avoid severe allergic reactions after another bite. By modulating the body’s immune system to produce tolerance to the allergen, desensitization therapy can protect these patients from 97% of anaphylaxis after another bite and reduce other allergic symptoms. Patients who develop systemic reactions but have negative allergy tests may have non-immune mechanisms that are not indicative of desensitization therapy. How can insect bites be avoided? In summer and early fall, wear long-sleeved white or light-colored clothing and shoes and hats; avoid trees and grass, be careful when approaching attics and eaves, and be especially careful when planting flowers and trees; be careful at picnics, cover food, do not drink from open beverage cans, and do not eat fallen or overripe fruit; do not wear perfume or use strongly scented soaps; do not walk barefoot or in sandals in grass; and when there are wasps or If you encounter many bees, you should cover your mouth and nose and run away quickly to find a shelter such as a car or house; close the windows and doors normally, and close the windows when driving; and keep the garbage cans placed outdoors covered.