What is red rash itching on the body?

Red rash itching on the body is very common in daily life. There are many diseases in dermatology that show itching and red rash, but in daily life, the most common ones are the following: 1. Prigo nodularis. Prigo nodularis is a chronic inflammatory skin disease. In the early stage, it will show a rash the size of rice grains, but it will gradually become larger and will be accompanied by severe itching. 2, papular urticaria, mosquito bites will release an acidic toxin in the skin, causing the skin to show red pimples and accompanied by itching. 3, prickly heat, hot summer due to high temperature, poor ventilation, covering the skin, the body will show prickly heat, usually needle-sized red pigment papules, and accompanied by itching. 4, drug rash, because the drug enters the human body, showing allergic reactions, the whole body will show erythema, papules with itching, and even fever.