Acne on the face, back and forehead is usually caused by folliculitis, acne and solar dermatitis. 1. Folliculitis: If you don’t pay attention to personal hygiene and skin cleanliness, it is easy to lead to Staphylococcus aureus or Malassezia infections, which will trigger folliculitis, resulting in the manifestation of pimples on the forehead, back, and face, which is usually accompanied by itching sensation. It can be treated with antibiotics such as fusidic acid and ceftazidime or antifungal drugs such as ketoconazole lotion as prescribed by the doctor. 2. Acne: Most common in adolescents, also known as pimples. When entering puberty, the level of androgen secretion rises, which can stimulate the secretion of sebaceous glands in hair follicles. The sebum discharge increases and easily clogs the pores, which leads to the appearance of pimples on the forehead, face and back. If you eat too spicy, greasy food, can also lead to acne, acne. 3. Solar dermatitis: Long-term exposure to strong ultraviolet rays can easily cause solar dermatitis, which can lead to erythema, papules, pimples, and herpes on exposed areas such as the face, chest, back, and hands, accompanied by itching and stinging. For acne on the face, back and chest, if other uncomfortable symptoms appear, it is recommended to go to the hospital in time.