Itchy limbs the more you scratch the more itchy pimples cause environmental factors, mosquito bites, hives and so on. 1. Environmental factors: If the weather is too hot and dry in the fall or winter, stimulate the skin to appear dehydrated phenomenon, which leads to the peripheral nerves in the skin is stimulated, triggering the patient due to the itching of the skin, to scratch, appearing pimples of symptoms. 2. Mosquito bites: If the patient’s limbs are mosquito bites, when the mosquito bites the skin, its secretion will stimulate the patient’s skin, triggering the patient’s skin itching, need to scratch to relieve, but also accompanied by localized skin pimples symptoms. 3. Urticaria: If the patient is allergic to food, pollen, drugs, etc., when in contact with these allergic substances, it will trigger its own immune system defense, resulting in a series of allergic reactions, such as itching of the limbs, edema, pimples and so on. If the patient appeared limbs itching more scratching more itchy pimples, it is recommended to go to the hospital in a timely manner to improve the relevant examination, to clarify the cause of the disease, and comply with the doctor’s instructions for treatment.