Swelling after mosquito bites is serious, consider the occurrence of insect bite dermatitis, you can apply local antipruritic drugs, hormones, etc., and severe symptoms can be treated with oral anti-allergy drugs. Insect bite dermatitis is also called papular urticaria, because of mosquito bites, the body of the mosquito saliva produces an allergic reaction, mainly manifested in the bite site of erythema, wind, itching and other sensations, serious cases can appear blisters, swelling and other manifestations. After the appearance of insect bite dermatitis, should pay attention to local hygiene, as little as possible scratching, to prevent infection; can be used locally to stop the itching of damphenol ointment. In addition, you can use topical glucocorticoids, such as dexamethasone cream, etc.; if the symptoms are serious, the swelling part of the body, you can take oral anti-allergy drugs, such as loratadine. In short, there is a mosquito bite after the swelling is serious, should promptly go to the hospital, under the guidance of the doctor for treatment.