Diagnosis and differential diagnoses

Diagnosis

  • Acne vulgaris is often clinically apparent and distinguished by the presence of pleomorphic lesions including comedones.
  • The presence of comedones is what distinguishes acne vulgaris from other cutaneous disorders.

Differential Diagnosis

  • The most common acne mimics are
  1. Rosacea
  2. Perioral dermatitis
  3. Folliculitis.

Diagnostic Methods

  • Acne vulgaris is usually diagnosed clinically by the presence of a pleomorphic collection of lesions including papules and pustules.

  • The presence of comedones is required for the clinical diagnosis of acne vulgaris.

  • In general, the diagnosis of acne vulgaris does not require laboratory testing. However, a thorough evaluation of a patient presenting with acne should include a complete history to rule out a systemic etiology of disease.

  • Rapid onset of acne associated with virilization should prompt laboratory testing of hormonal levels and imaging studies to rule out an underlying adrenal or ovarian tumor.

  • Elevated serum androgens are found in patients with severe cystic acne and in association with endocrine abnormalities or neoplastic processes.

  • The majority of patients with acne have normal levels of serum androgens.

  • Additionally, a complete medication list should be obtained to rule out medication-induced acne.

  • Physical examination should focus on the type and location of lesions, scarring, keloids, and postinflammatory pigmentary changes.