Acne is a primary inflammatory disorder involving the pilosebaceous unit. The pathogenesis is multifactorial, involving four key factors with interrelated mechanisms: increased sebum production, hyperkeratinization of the follicular infundibulum, inflammation, and Cutibacterium acnes (formerly Propionibacterium acnes).
Global classifications of dermatologists correlate with numbers of inflammatory eruptions (papules plus pustules), but not with numbers of comedones. The appropriate divisions of inflammatory eruptions of half of the face to decide classifications are: 0-5, “mild”; 6-20, “moderate”; 21-50, “severe”; and more than 50, “very severe”.
The Global Acne Grading System
| Location | Factor (F) | Severity (S) | Local Score (F × S) |
| Forehead Right Cheek Left Cheek Nose Chin Chest and upper back |
2 2 2 1 1 3 |
0: Nail 1: Comedone 2: Papules 3: Pustule 4: Nodule |
Mild: 1-18 Moderate: 19-30 Severe: 31-38 Very Severe > 39 |
Algorithm for the Management of Acne Vulgaris
| Treatment | Mild Acne | Moderate Acne | Severe Acne |
| First-line treatment | Benzoyl peroxide, topical retinoid, or topical combination therapy | Topical combination therapy; oral antibiotic, topical retinoid, and benzoyl peroxide; oral antibiotic plus topical retinoid; or benzoyl peroxide plus topical antibiotic | Oral antibiotic plus either topical combination therapy or oral isotretinoin |
| Alternative treatment | Add topical retinoid or benzoyl peroxide (if not using already), or consider alternative retinoid, or consider topical dapsone | Consider alternative combination therapy, or consider change in oral antibiotic, or add combined oral contraceptive or oral spironolactone (in female patients), or consider oral isotretinoin | Consider change in oral antibiotic, or add combined oral contraceptive or oral spironolactone (in female patients), or consider oral isotretinoin |
* Topical combination therapy (benzoyl peroxide and antibiotic agent; retinoid and benzoyl peroxide; or retinoid, benzoyl peroxide, and antibiotic) may be prescribed as a fixed-dose combination product or as separate components.
References:
- Zaenglein AL. Acne Vulgaris. N Engl J Med. 2018 Oct 4;379(14):1343-1352. [Medline]
- Trivedi MK, Bosanac SS, Sivamani RK, Larsen LN. Emerging Therapies for Acne Vulgaris. Am J Clin Dermatol. 2018 Aug;19(4):505-516. [Medline]
Created: Apr 01, 2019.
