Dandruff and acne can be related because scalp flakes and oil can fall onto the face and clog pores, so first control dandruff by using an anti-dandruff shampoo with Ketoconazole 2?3 times a week and keep your scalp clean; for acne, wash your face twice daily with a gentle cleanser.

It seems you are referring to a herpes infection (Herpes simplex), which can leave dark spots after healing; for active infection, antiviral medicines like Acyclovir are usually prescribed by a doctor, and for the remaining spots (post-inflammatory pigmentation), you can use mild creams with ingredients like vitamin C or niacinamide to gradually lighten them. if new blisters or pain appear, consult a doctor for proper antiviral treatment.