Usually the onset of urticaria may be related to environmental hygiene conditions, but it is not entirely caused by the environment, for example, food, medications, mental factors, and autoimmunity can induce urticaria. If the environment in which you live is humid and dirty, creatures such as mosquitoes and fleas are likely to appear, and when mosquitoes bite, patients may develop hives symptoms. In addition, poor environmental hygiene may breed mites and other parasites that infect the body, stimulating the local skin and inducing the occurrence of urticaria. 1, mosquito bites: as mosquitoes, fleas, caterpillars and other bites on the human body, secrete saliva mixed with anthranilic acid and other toxic substances, stimulating the body to produce an immune response, resulting in a significant local rash. For allergic patients often cause papular urticaria, manifested as scattered or clustered blister-like papules, slightly harder than normal skin texture, patients feel itchy. Such urticaria can generally subside on its own in about 1-2 weeks, but being in a dirty environment for a long time may lead to recurrent attacks; 2. Parasitic infections: mite infections are generally common. Dust mites are the most important mites that cause atopic dermatitis and can breed in many places such as carpets, sofas, bed sheets and bedding. Mites such as wormy mites and scabies mites are often parasitic in human sebaceous glands, stealing nutrients from the skin and making the epidermis fragile and intolerant. The mites feed on human sweat, secretions and dander, and are extremely fertile, and their bodies and excretions are allergenic. As a result of not cleaning the home environment or cleaning the skin in time, it is not possible to remove the mite carcasses, secretions and excretions, nor to stop the mites from reproducing, which enhances the incidence of urticaria. It is important to note that patients should regularly change and disinfect bed sheets, covers, sofa sets, cushions, carpets, plush toys and other things to use, timely cleaning of garbage and dark and damp corners of the home to maintain a clean and tidy living environment, while doing a good job of cleaning their own skin is very important to reduce the breeding of mosquitoes, and more help prevent the onset of hives. Patients with urticaria attacks can use topical Furamyl lotion, compound dexamethasone acetate cream, erythromycin ointment, mometasone furoate cream and other drugs under the guidance of a doctor, or take oral cetirizine, loratadine and other drugs to reduce inflammation and anti-allergy.