Management of acne should involve combined treatment that targets as many of the underlying pathogenic factors as possible, according to new expert committee recommendations from the American Academy of Pediatrics.
The new document is adapted from a 2003 consensus report issued by an international group of dermatologists called the Global Alliance to Improve Outcomes in Acne. Their recommendations were based on evidence whenever possible, but also included expert opinion based on clinical experience (J. Am. Acad. Dermatol. 2003;49[suppl. 1]:S1–37).
That report was never published in the pediatric literature. The new AAP statement, which also includes data from articles published since 2003, “is essentially a reworking of the information for pediatricians,” said lead author Dr. Andrea L. Zaenglein, of the departments of dermatology and pediatrics at Pennsylvania State University, Hershey, in an interview.
Three basic principles underlie the recommendations, which were supported by an unrestricted educational grant from Galderma Laboratories L.P. (Pediatrics 2006 [Epub doi.10.1542/peds.2005–2022]):
▸ A topical retinoid should be the foundation of treatment for most patients with acne. Retinoids target the microcomedo, the precursor to all lesions. They are also comedolytic and have intrinsic anti-inflammatory effects, thus targeting two pathogenic factors in acne.
▸ Combining a topical retinoid with an antimicrobial agent targets three pathogenic factors. Clinical trials have shown that combination therapy results in significantly faster and greater clearing, as opposed to antimicrobial therapy alone.
▸ Oral antibiotics should be used only in moderate to severe acne and should not be used as monotherapy. They should be discontinued as soon as possible, usually within 8–12 weeks.
Depending on the degree of inflammation, topical retinoids may be used alone (when comedones predominate), or with an antimicrobial agent. Female patients also may benefit from hormonal therapy with oral contraceptives.
For severe acne, treatment with oral isotretinoin is recommended. Isotretinoin therapy should also be considered for cases of acne refractory to conventional therapy with a topical retinoid, benzoyl peroxide, and oral antibiotic therapy, Dr. Zaenglein and her associates said.
The central role of topical retinoids in treating both comedonal and inflammatory acne was new in the 2003 document. Before that, topical retinoids had been reserved primarily for patients with comedonal acne, the authors noted.
Because topical retinoids may cause burning and irritation, particularly during the early weeks of therapy, it's important to ask patients about the products they've tried previously and how well those were tolerated. The vehicle must be considered in the selection of a retinoid because some are more irritating than others. Alcohol-based gels are generally more irritating than are cream-based products, for example.
Educating the patient about starting off slowly—such as every second or third day—and using the medication for a shorter duration of contact (for example, by washing it off after a period of time) may improve compliance. Patients also should be warned not to use any concurrent over-the-counter medications, such as salicylic acid scrubs or astringents, which can increase irritation when used with a retinoid.
The three topical retinoids currently approved for use in the United States—tretinoin, adapalene, and tazarotene—decrease formation of microcomedos and subsequent acne lesions. The main difference is in cutaneous tolerability, which can vary among formulations. The document outlines the clinical data on each product.
Combination therapy—including a topical retinoid with either a topical or an oral antibiotic and benzoyl peroxide—is considered the standard of care for the majority of acne patients. Benefits include targeting different pathophysiologic factors, such as abnormal desquamation, proliferation of Propionibacterium acnes, and inflammation; increasing efficacy; improving the speed of lesion resolution; and minimizing the potential for antibiotic resistance, the authors said.
Antimicrobials were long considered a mainstay in the treatment of acne vulgaris. Now, in a climate of increasing antibiotic resistance, they are recommended as adjunctive rather than primary acne treatment. Topical antibiotics are indicated for mild inflammatory acne. They are typically well tolerated apart from occasional mild cutaneous irritation and burning. The topical macrolides erythromycin and clindamycin may be used alone or in combination with benzoyl peroxide.
Benzoyl peroxide is the most potent topical antimicrobial, with rapid bactericidal action. It is effective when used alone or combined with other antibiotics. It is available in many different formulations, including soaps, washes, creams, gels, and lotions, in concentrations of 1%–10%. Skin irritation is a common side effect, but it generally improves with time, they said.
Oral antibiotics should be reserved for patients with moderate to severe inflammatory acne. Tetracycline and the tetracycline derivatives doxycycline and minocycline are the most common agents; alternative choices include macrolides, cotrimoxazole, and trimethoprim. After improvement is noted, the oral antibiotic should be discontinued as soon as possible. If no improvement is seen within 8–16 weeks of initiation, a change in antibiotic is warranted because resistance is likely. When the patients stop oral therapy, they should continue with topical retinoid therapy to maintain improvement.