Frequent pimples on the face and forehead with red marks can be related to acne, and dandruff on the scalp can sometimes worsen forehead acne because flakes and oil irritate the skin. To manage both problems, wash your face twice daily with a gentle or salicylic acid?based face wash to keep pores clear, and avoid touching or squeezing pimples to prevent marks. Using a topical treatment such as benzoyl peroxide, adapalene, or a doctor-recommended retinoid can help control acne and gradually reduce red spots. For dandruff, use an anti-dandruff shampoo containing ketoconazole, zinc pyrithione, or selenium sulfide 2-3 times a week, leaving it on the scalp for a few minutes before rinsing. Keep the scalp clean, avoid heavy hair oils, and try to keep hair away from the forehead. If pimples, dandruff, or marks continue despite these steps, it is best to consult a dermatologist who can prescribe stronger treatments if needed.