Caterpillar-induced skin redness and swelling may be caused by caterpillar dermatitis, which can be improved by removing the poisonous hairs, medication and strengthening protection. 1. Remove the poisonous hairs: The poisonous hairs or spines of caterpillars contain many kinds of toxins and are very easy to fall off, and when they penetrate into the skin, they will stimulate the skin to produce erythema, maculopapular rash, acne and other damages, accompanied by intense itching, so the first thing to pay attention to in treatment is to remove the poisonous hairs as much as possible. Soap, grass ash and other alkaline detergent can be used immediately to scrub the contact area, you can also use zinc oxide ointment, transparent tape and other items repeatedly paste the lesion area to help remove the poisonous hairs. 2. Medication: For patients with mild symptoms of skin redness and swelling caused by caterpillars, you can apply 1% peppermint glycerite lotion, glucocorticosteroid creams (such as tretinoin cream and hydrocortisone cream) and other medications to help stop the itching and eliminate the redness and swelling. For patients with more serious symptoms of skin redness and swelling, combined with intense itching, oral antihistamines (such as loratadine, levocetirizine) should be taken at the same time, and those who are ineffective can take oral glucocorticosteroids (such as hydrocortisone, dexamethasone) and other anti-inflammatory and anti-allergy treatments. 3. Enhanced protection: During the above treatment, attention should be paid to enhanced protection to avoid re-exposure to caterpillars, such as: the use of drugs to eliminate caterpillars, wear protective clothing and hats and so on. It should be noted that the above treatment should be carried out under the guidance of physicians to avoid the occurrence of adverse reactions.