Red swelling with blisters after being bitten by insects, consider the appearance of insect bite dermatitis, and you can choose the following treatment plan in clinical treatment: 1, oral medicine: you can apply Avastin capsule or fexofenadine hydrochloride tablet orally to strengthen the treatment effect of anti-itch and anti-allergy; at the same time, because the redness and swelling mostly belong to heat poison incandescence and cause, so you can take Pientzehuang tablet or apply Buxin Xia Taje capsule orally to cool blood, detoxify and 2. External medicine: you can apply compound polymyxin B ointment or mupirocin ointment for anti-inflammatory and swelling treatment, and then apply mometasone furoate cream or fluticasone propionate cream for treatment after the redness and swelling subsides.