Chapter 112. Acne Vulgaris

A 16-year-old boy (Figure 112-1) with severe nodulocystic acne and scarring presents for treatment. After trying oral antibiotics, topical retinoids, and topical benzyl peroxide with no significant benefit, the patient and his mother request isotretinoin (Accutane). After 4 months of isotretinoin, the nodules and cysts cleared and there remained only a few papules (Figure 112-2). He is much happier and more confident about his appearance. The skin cleared fully after the last month of isotretinoin.

Acne is an obstructive and inflammatory disease of the pilosebaceous unit predominantly found on the face of adolescents. However, it can occur at any age and often involves the trunk in addition to the face.

Acne vulgaris affects more than 80% of teenagers, and persists beyond the age of 25 years in 3% of men and 12% of women.1

The four most important steps in acne pathogenesis:

1. Sebum overproduction related to androgenic hormones and genetics.

2. Abnormal desquamation of the follicular epithelium (keratin plugging).

3. Propionibacterium acnes proliferation.

4. Follicular obstruction, which can lead to inflammation and follicular disruption.

Neonatal acne is thought to be related to maternal hormones and is temporary (Figure 112-3).

Acne can be precipitated by mechanical pressure as with a helmet strap (Figure 112-4) and medications such as phenytoin and lithium (Figure 112-5).

There are some studies that suggest that consumption of large quantities of milk (especially skim milk) increase the risk for acne in teenagers.2

Clinical Features

Morphology of acne includes comedones, papules, pustules, nodules, and cysts.

• Obstructive acne = comedonal acne = noninflammatory acne and consists of only comedones ...