Mosquito bites a big bag is usually insect bite dermatitis, there is no how to reduce the swelling of the fastest statement, you can relieve or improve the symptoms through general treatment, medication and so on. 1. General treatment: you should keep the skin clean, avoid scratching and squeezing, after rinsing with water, you can use a cool towel, ice cold compresses can reduce local edema, help the recovery of the disease. 2. Drug treatment: you can use glycerine lotion, can play the role of anti-itching, astringent; can also take oral antihistamines, such as loratadine, cetirizine, etc.. If necessary, topical glucocorticoid drugs, such as compound dexamethasone ointment, can be used under the guidance of a doctor. If combined with bacterial infection, it is recommended to use topical mupirocin, etc., and oral treatment with sensitive antibiotics. It is recommended that patients who have been bitten by mosquitoes with large bags go to regular hospitals in a timely manner, under the guidance of a professional doctor, to avoid their own abuse of drugs causing serious adverse reactions.