Systems for the grading and classification of acne: Recommendations

What systems are most commonly used for the grading and classification of adult acne and acne vulgaris in adolescents (11 to 21 years) to adults?

  • Clinicians may find it helpful to use a consistent grading/classification scale (encompassing the numbers and types of acne lesions as well as disease severity, anatomical sites, and scarring) to facilitate therapeutic decisions and assess response to treatment.
  • Currently, no universal acne grading/classifying system can be recommended.

Strength of Recommendation: B Level of Evidence: II, III

Acne grading systems may be useful in patient care. Such systems can assist in more specific classification of disease, determining appropriate treatment options, and monitoring improvement during the treatment course.

Numerous acne assessment tools have been described, taking into account various factors such as type of acne, severity of acne, number of acne lesions, anatomical location/extent of acne,8 quality of life and other psychosocial metrics,9-13 and scarring,14 among other measures.15-24 Recently, eighteen of these grading scales were ranked based on a variety of characteristics.25 To date, there is no universally agreed upon grading system, and systems can differ greatly between studies. Furthermore, inter-observer reliability of these scales varies, but has been poor in some studies.17, 26, 27 Methods such as photographic standards have been employed to improve reproducibility.

Improvements in digital technology, photographic equipment, and teledermatology may allow for accurate, remote assessment of acne in the near future.28-30 Scientific measures such as ultraviolet-induced red fluorescence,31-33 casual sebum level,34, 35 skin capacitance imaging,36 skin surface pH,37, 38 and transepidermal water loss39 may also help to more objectively classify and rate acne in the future. Reproducibility, as well as ease of use and acceptance by dermatologists, will be essential for the success of any grading system. 

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