Acne on the back and arms can be caused by diseases such as folliculitis, acne, and keratosis pilaris.
1. Folliculitis: most folliculitis is caused by infection of hair follicles and their surrounding tissues due to bacteria, fungi and other pathogens. It can occur in any part of the body where there are hair follicles, and manifests itself in the form of red papules and pustules around the hair follicles, which may be accompanied by itching, pain and other symptoms.
2. Acne: It is a chronic inflammatory disease of the sebaceous glands of the hair follicles due to a variety of factors. It is most common in teenagers and can occur on the face, chest, back and other parts of the body, manifesting as pimples, papules, pustules, nodules and so on.
3. Perifollicular keratosis: the cause of the disease is not yet clear, may be related to genetics, vitamin A deficiency, etc., is a chronic follicular keratosis pilaris, common in the outer upper arm and thigh extensor keratotic papules, chicken skin-like, skin with roughness, usually no self-conscious symptoms.
Acne on the back and arm may also be due to other diseases, it is recommended that patients seek medical attention in a timely manner, and actively cooperate with the relevant examination, in order to clarify the cause of the disease, targeted treatment.