Chapter 5: Acneiform Disorders
Acne Vulgaris
What is acne?
Acne vulgaris is one of the most common skin conditions worldwide. It is most common in teenagers but can be seen in preteens and adults as well. Most people can recognize acne by its blackheads, whiteheads, and pimples. It is most often seen on the face, back, and chest.
What causes it?
There are several factors that contribute to the development of acne.
- Increased sebum production in response to androgens.
- Follicular hyperkeratosis that blocks the opening of hair follicles and causes comedones (whiteheads – or closed comedones, and blackheads – or open comedones).
- Cutibacterium acnes (C. acnes), formerly known as Proprionibacterium acnes, proliferation around the hair follicle.
- Inflammation, which causes pustules and nodules. These inflammatory lesions may lead to scarring.
There are many myths or misconceptions about acne. It is helpful to reassure patients that:
- Acne is not caused by dirty skin. In fact, washing the face too often can make acne worse because of irritation.
- Diet does not have a large role in acne formation. There is some evidence that high glycemic diets may worsen acne, but this is not the underlying cause. There are also other health benefits to following a lower glycemic diet.
- Stress does not cause acne, but it can make it flare.
What does it look like?
Mild acne presents with comedones primarily on the cheeks and forehead. These can be open (blackheads) or closed (whiteheads) and have little inflammation associated with them. In moderate acne, there are inflammatory papules and pustules, and sometimes nodules, which are deeper than the comedones and may involve the back and chest. In more severe acne cystic lesions appear, and scarring results as these heal.
How is it treated?
Treatment of acne requires long-term therapy.
Mild acne: Topical therapy is often sufficient. These may include over-the-counter salicylic acid or benzoyl peroxide washes, creams, and wipes. For primarily comedonal acne, topical retinoids work well. For small inflammatory lesions, benzoyl peroxide, topical antibiotics or combination products are more effective. An alternate agent is azelaic acid.
Moderate acne generally requires oral therapy, often in combination with topicals. For papular/pustular and nodular acne oral antibiotics such as doxycycline taken for several months are often recommended. In female patients a combined oral contraceptive pill may be a good option. These may be used in combination with the topical products described above.
For acne that is severe, scarring or unresponsive to the above treatments, isotretinoin is the first line therapy. Isotretinoin has the best chance of “curing” acne, though some patients do need more than one course. Due to the side effect profile, patients taking isotretinoin must be carefully counselled and monitored. Lab monitoring includes liver function, lipids and pregnancy tests.
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