Figure 1

Inflammatory disorder of pilosebaceous follicles with a 90% prevalence in adolescence and young adulthood.

Etiology: Abnormal follicular keratinization, increased sebum 2° to androgens, Propionibacterium acnes (bacteria), inflammation.

Genetic factors; occlusive cosmetic agents; medications: steroids, ACTH, androgens, danazol, iodides, lithium, antiepileptics, oral contraceptives; diseases: congenital adrenal hyperplasia (CAH), polycystic ovarian syndrome (PCOS); worse with emotional stress.

History: Often asymptomatic lesions (especially comedones), although can be tender (nodules).

Physical: Two types of lesions, predominantly affect face, neck, chest and back.

1. Noninflammatory—open ("black heads") and closed ("white heads") comedones.
2. Inflammatory—papules, pustules, cysts, nodules; deep lesions leave scars, inflammatory papules, pustules & nodules on back and check with early scarring.

DDx: Folliculitis, perioral dermatitis, rosacea

Investigations: If irregular periods, hirsutism, virilization, or not responding to conventional therapy, work-up to rule out virilizing tumor or PCOS.

See Topic(s):

Management

• Treatment Options Based on Acne Type
• Selected Topical Medications for the Treatment of Acne
• Selected Systemic Medications Acne Treatment
• Other Considerations