A 16-year-old boy (Figure 118-1) with severe nodulocystic acne and scarring presents for treatment. After trying oral antibiotics, topical retinoids, and topical benzoyl peroxide with no significant benefit, the patient and his mother requested isotretinoin (Accutane). After 4 months of isotretinoin, the nodules and cysts cleared, and only a few papules remained (Figure 118-2). He is much happier and more confident with his appearance. His skin cleared fully after 6 months of isotretinoin.
Severe nodulocystic acne with scarring in a 16-year-old boy. (Reproduced with permission from Richard P. Usatine, MD.)
A happier boy now that his nodules and cysts have cleared at the start of the fifth month of isotretinoin treatment. (Reproduced with permission from Richard P. Usatine, MD.)
Acne is an obstructive and inflammatory disease of the pilosebaceous unit predominantly found on the face, but it may also involve the trunk. It can occur at any age, but it is most common during adolescence.
Acne vulgaris affects more than 80% of teenagers and persists beyond the age of 25 in 3% of men and 12% of women.1 Neonatal acne is most often benign cephalic pustulosis. It is temporary and thought to be related to Malassezia species (Figure 118-3) (see Chapter 114, Normal Skin Changes).
Neonatal acne in a healthy 2-week-old infant that resolved without treatment. (Reproduced with permission from Richard P. Usatine, MD.)
ETIOLOGY AND PATHOPHYSIOLOGY
The four most important steps in acne pathogenesis are:
Sebum overproduction related to androgenic hormones and genetics
Abnormal desquamation of the follicular epithelium (keratin plugging)
Propionibacterium acnes proliferation
Follicular obstruction, which can lead to inflammation and follicular disruption
Acne can be precipitated by mechanical pressure such as a helmet strap (Figure 118-4) and medications such as phenytoin and lithium (Figure 118-5).
Inflammatory acne showing pustules and nodules in a 17-year-old boy who uses a helmet while playing football in high school. (Reproduced with permission from Richard P. Usatine, MD.)
Severe inflammatory acne in a young adult. His acne worsened when he was started on phenytoin for his seizure disorder. (Reproduced with permission from Richard P. Usatine, MD.)
Some studies suggest that ...