How is acne vulgaris diagnosed?

There is no validated and universal way to diagnose acne vulgaris. Many definitions and grading scales exist, and most grading scales use photographs and the number of acne lesions to quantify the severity of acne vulgaris from mild to severe.^[1]

• Mild acne: noninflammatory lesions, few inflammatory lesions, or both
• Moderate acne: more inflammatory lesions, occasional nodules that form as hard, painful lesions, and mild scarring
• Severe acne: extensive inflammatory lesions, nodules, and scarring, ongoing moderate acne that has not improved with treatment after 6 months, or any acne that causes serious psychological distress^[2]

The diagnosis of acne vulgaris should be based on the clinical judgment of a medical professional.