MKSAP Quiz: Acne breakout for 6 months

A 16-year-old woman is evaluated for an acne breakout on her face of 6 months' duration. She has been using over-the-counter benzoyl peroxide products, but the acne is not improving. After a history and physical, what is the most appropriate treatment?


A 16-year-old woman is evaluated for an acne breakout on her face for 6 months' duration. She has been using over-the-counter benzoyl peroxide products, but the acne is not improving. She is not sexually active. Medical history is unremarkable, and she takes no medications.

On physical examination, vital signs are normal. Skin findings show scattered open and closed comedones on the forehead, nose, and cheeks. There are no inflammatory pustules or nodules. The remainder of the examination is normal.

Which of the following is the most appropriate treatment?

A. Isotretinoin
B. Oral contraceptive pills
C. Topical antibiotics
D. Topical retinoids


MKSAP Answer and Critique

The correct answer is D. Topical retinoids. This content is available to MKSAP 18 subscribers as Question 55 in the Dermatology section. More information about MKSAP is available online.

This patient has comedonal acne and should be treated with a topical retinoid. Treatment begins by considering the types and distribution of lesions, as well as the pregnancy status of the female patient. Interventions are selected with the goal of modifying the main causal factors, such as follicular occlusion, sebum production, Propionibacterium acnes proliferation, and inflammation. Comedonal acne consists of open and closed comedones (blackheads and whiteheads, respectively) with no inflammatory papules or pustules. First-line treatment for most patients with comedonal acne is topical retinoid. Topical retinoids are the only choice that is comedolytic and normalizes keratinization of the hair follicle. Topical retinoids are also effective in treating inflammatory acne. Because retinoids are preventive, they need to be applied to the entire acne-prone area and not used as a spot treatment. The most common adverse effects are dryness and irritation.

Isotretinoin is an oral retinoid used to treat severe nodulocystic acne with scarring or when other traditional therapies have failed. This patient does not have evidence of scarring or cystic lesions and has not previously failed any other prescription therapies. Isotretinoin is teratogenic, and use requires that providers, patients, and pharmacies must be registered in the iPLEDGE program, an FDA-approved regulatory program to prevent birth defects, and complete monthly reports. Patients must use two forms of birth control in order to be eligible for isotretinoin therapy.

Oral contraceptive pills are more effective in inflammatory and adult acne, which is characterized by inflammatory papules and cystic lesions along the jawline. Oral contraceptive pills have been shown to reduce comedones, but are not as effective as topical retinoids for comedonal acne.

Topical antibiotics are important in inflammatory acne when pustules and inflammatory papules are present. They work to inhibit P. acnes and decrease inflammation. They are not comedolytic and would not be effective in treating comedonal acne. Owing to the increased incidence of antibiotic resistance, topical antibiotics should not be used as monotherapy. Benzoyl peroxide is available over the counter and is an excellent complement to treatment with an oral or topical antibiotic, as it reduces the development of bacterial resistance.

Key Point

  • Topical retinoids are first-line treatment for comedonal acne because they are comedolytic and normalize keratinization of the hair follicle.