Enlarged pores and dark hairs on the back can be caused by acne, Malassezia folliculitis, polycystic ovary syndrome and other diseases, which need to be treated with medication. 1. Acne: Acne can also cause large pores and dark hairs on the back of women. Topical retinoids, such as tazarotene gel, can dissolve acne, improve keratinization and relieve symptoms. 2. Malassezia folliculitis: Women with large pores and black hairs on their backs can also be caused by Malassezia folliculitis, which can be applied under medical supervision, such as ketoconazole, econazole cream and other antifungal drugs. When the inflammation is severe, oral antifungal drugs such as fluconazole and itraconazole can be taken as prescribed by the doctor. 3. polycystic ovary syndrome: polycystic ovary syndrome caused by women’s back pores with black hair, can be under the guidance of the doctor oral anti-androgen drugs, such as spironolactone, compound cyproterone acetate, and so on. It can inhibit the secretion of androgen, thus improving the symptoms. There are many reasons that cause women to have enlarged pores and black hairs on the back, so it is recommended that patients go to the hospital in time to clarify the cause of the disease and standardize the treatment under the guidance of the doctor.