Red pimples on the body may be caused by allergies, acne, chicken pox and other reasons. 1. Allergy: If the patient is allergic to something that can easily cause allergies, such as seafood or pollen, an allergic reaction may lead to red pimples on the skin, usually accompanied by obvious itching symptoms. 2. Acne: Acne is a relatively common skin disease, more common among young people, usually occurs on the chest and back and other parts of the body, the patient may appear red pimples, usually no obvious itching, but the duration of the pimples is usually longer. 3. chickenpox: chickenpox is caused by chickenpox – herpes zoster virus infection caused by an acute infectious diseases, children are common, red blisters pimples can occur in the trunk, limbs and other parts, no obvious itching. Red pimples on the body may also be caused by other reasons, it is recommended to actively go to the regular hospital, to clarify the specific causes, and then targeted treatment.