The most common disease for a 20-year-old girl with acne on her face is acne, and its treatment includes general treatment, localized treatment, and systemic treatment. 1. General treatment: choose suitable cleansing products to remove excess oil on the skin surface, pay attention to oil control and moisturizing; dietary restrictions on sugar and high protein food intake, and develop good work and rest habits. 2. Topical treatment: For mild symptoms, topical medications such as retinoic acid cream, benzoyl peroxide lotion, fusidic acid cream, etc. can be used; more severe acne and acne scars can be treated with red and blue light irradiation, photodynamic therapy, fractional laser and other methods. 3. Systemic treatment: For moderate to severe acne, systemic medication is required, which involves the use of isotretinoin, antibiotics, and even glucocorticoids under the guidance of a doctor. Commonly used antibiotics are doxycycline, minocycline, etc.; for polymerization or violent acne can be used in the appropriate amount of prednisone, severe nodular acne can choose steroid hormone injections. In addition to acne, a 20-year-old girl with acne on her face may also have folliculitis, which is usually treated with topical antibiotics such as mupirocin. It is recommended that patients with acne on the face go to the hospital in time.