Acne Vulgaris

Initial Evaluation

Determine the type, severity, and location of acne, and presence of scarring.

Acne lesions

Non-inflammatory (comedones)

Inflammatory (papules-pustules-nodules)

Scars (Keloidal scarring is present on the central chest. The other three images show atrophic scarring on the face.)

Types of acne

Comedonal acne: Open (blackheads) and closed (whiteheads) 1-2 mm follicular-based papules. Some of the lesions are excoriated.

Inflammatory acne: The lesions of inflammatory acne include erythematous papules and pustules, nodules and cysts. These are often seen in conjunction with comedones.

Nodular acne: Nodules are present on the upper right forehead and bilateral medial cheeks, in addition to inflammatory papules, pustules, and scars.

Neonatal acne: Inflammatory papules and milia on the cheeks of an infant (left) and inflammatory papules and pustules (middle) and crusted papules (right).

Acne with scarring: Atrophic acne scars in the setting of inflammatory papules and pustules (left) and keloid formation (right).

Severity of acne

  • Mild-to-moderate: mostly facial, usually non-scarring, mostly comedones, papules, and pustules
  • Moderate-to-severe: numerous lesions, can also involve the trunk, may scar, comedones, papules, pustules, nodules or cysts present
  • Severe: presence of scarring in the setting of comedones, papules, pustules, nodules or cysts, involvement of trunk is common

See the chapter Acne Vulgaris in A Clinical Atlas of 101 Common Skin Diseases.

Exacerbating factors

  • Presence of hormonal imbalances (polycystic ovary syndrome, oral contraceptives, exogenous androgens) or clear history of exacerbation related to menses
  • Systemic medications (anabolic or corticosteroids, OCPs, psychiatric medications, chemotherapy)
  • Occlusive topical agents
  • Mechanical irritation
  • Self-manipulation of lesions (picking)
  • The role of diet, sun exposure, and smoking are controversial

Differential diagnosis


Seborrheic dermatitis

Pityrosporum or other infectious folliculitis