People may apply antibiotics to the skin or take them orally to treat acne. They work by killing "C. acnes" and reducing inflammation. Although multiple guidelines call for healthcare providers to reduce the rates of prescribed oral antibiotics, many providers do not follow this guidance. Oral antibiotics remain the most commonly prescribed systemic therapy for acne. Widespread broad-spectrum antibiotic overuse for acne has led to higher rates of antibiotic-resistant "C. acnes" strains worldwide, especially to the commonly used tetracycline (e.g., doxycycline) and macrolide antibiotics (e.g., topical erythromycin). Therefore, dermatologists prefer antibiotics as part of combination therapy and not for use alone.