The common causes of many red pimples on forehead include acne, folliculitis, seborrheic dermatitis, etc. The treatments include medication, physical therapy and surgery. 1. Acne: Acne is a common chronic inflammatory disease of the sebaceous glands of the hair follicles, often associated with dietary habits, mental stress and other factors. Adopting a healthy diet and maintaining an optimistic mindset can alleviate the symptoms. Medications include isotretinoin, clindamycin, benzoyl peroxide, etc. Physical therapy includes laser treatment. 2. Folliculitis: Folliculitis is caused by bacteria, fungi and other microorganisms. Obesity, decreased immunity and other factors are easy to induce the development of the disease. Commonly used drugs include mupirocin, cefuroxime, etc. If the condition is serious, it can be drained through surgical incision. 3. Seborrheic dermatitis: seborrheic dermatitis is a chronic inflammatory dermatosis, patients mainly manifested in the face of diffuse erythema often accompanied by flaking. Drug treatment has tacrolimus, ketoconazole, vitamin B6 and so on. It is necessary to choose the appropriate drugs under the guidance of the doctor. When the patient is not feeling well, he should go to the hospital immediately and follow the doctor’s instructions to use medication.