Acne vulgaris is a chronic inflammatory dermatosis which is notable for open and/or closed comedones (blackheads and whiteheads) and inflammatory lesions including papules, pustules or nodules.
Mild acne has <20 comedones or <15 inflammatory lesions or <30 total lesion count.
Moderate acne has 20-100 comedones or 15-20 inflammatory lesions or 30-125 total lesion count.
Severe papules/pustules or nodulocystic acne is the acne resistant to topical treatment or if scarring/nodular lesions are present.

Differential Diagnosis

  • Formation of comedones is inherent to the diagnosis of acne vulgaris and when not evident, the following diagnoses may be considered: Keratosis pilaris, perioral dermatitis, rosacea, folliculitis, miliaria, hidradenitis suppurativa


  • Consider a referral to an expert or specialist if there is significant scarring or goals of treatment were not met
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