The appearance of itchy bumps on the arms requires careful observation of the appearance of the bumps. If the bumps exist in isolation and may be accompanied by mild swelling, consider them to be papular urticaria caused by mosquito bites. Oral medications and topical medications are recommended. Oral cetirizine tablets or ketotifen tablets are recommended. Furfuracin lotion can be applied to the bumps, and dehumidifying and antipruritic cream can also be used as an option to effectively relieve the itchiness of the bumps and accelerate the fading of the symptoms. If the bumps are symmetrically distributed and can be accompanied by blistering and exudation, it is considered acute eczema. It is recommended to choose saline wet compresses with Eloson cream or Paregoric Pine cream, which has a good receding effect, and try using 0.1% tacrolimus ointment.