New guidelines issued for acne therapy
In its recently issued Guidelines of Care for Acne Vulgaris Management, the American Academy of Dermatology presents evidence-based recommendations for treating adolescents and adults with this common disorder.
“Acne is often treated by primary-care clinicians,” says Abby S. Van Voorhees, MD, assistant professor of dermatology at the University of Pennsylvania, in Philadelphia, and a member of the work group that wrote the Guidelines. “What we want to emphasize for them is the importance of approaching acne from multiple therapeutic perspectives, even in relatively minor cases with limited involvement. Also, which patients are appropriate to screen—for hormonal components, for example—and which are not.”
Microbiologic testing is not routinely indicated for acne; when bacterial involvement is implicated in the inflammatory phase of the condition, the characteristic organism is Propionibacterium acnes, a gram-positive anaerobe. Bacterial culture should be considered, however, when pustules or nodules (typically in the perioral and nasal regions) suggest gram-negative folliculitis, which is less likely to respond to conventional antibiotics.
Endocrinologic screening should also be used selectively. “Not every 15-year-old with a few pimples needs an extensive evaluation, but there are some situations in which it is very appropriate,” Dr. Van Voorhees says. The Guidelines recommend testing when history or signs and symptoms beyond the acne itself suggest hyperandrogenism. For prepubertal children, these include body odor, axillary or pubic hair, genital maturation, or such other manifestations of early maturation as accelerated growth. A hand film to detect advanced bone age can provide a useful screen before more detailed testing.
In older females, infrequent menses, hirsutism, alopecia, infertility, polycystic ovaries, clitoromegaly, and truncal obesity are indications of virilization that might prompt a fuller evaluation by a gynecologist or endocrinologist.
The application of such topical agents as retinoids, benzoyl peroxide, and antibiotics is standard of care for acne of varying levels of severity, according to the Guidelines. “Most patients with more limited disease will do nicely with topicals under the care of their clinician,” Dr. Van Voorhees says. Combination regimens appear particularly helpful.
Ample evidence supports the efficacy of topical retinoids for both comedonal and inflammatory acne. No specific preparation (e.g., tretinoin, adapalene) is clearly superior, and the concentration and vehicle may influence tolerability. Benzoyl peroxide has also been proven effective; it seems to have particular utility, in combination with oral or topical antibiotics, for preventing the development of P. acnes resistance. In topical formulations, the antibiotics erythromycin and clindamycin appear to be effective and well tolerated.
The Guidelines note that topical regimens calling for a combination of antibiotics with retinoids or benzoyl peroxide are more effective than any individual component. Preparations combining antibiotics and benzoyl peroxide have been available for several years, and the first to combine an antibiotic (clindamycin) with a retinoid (tretinoin) was approved by the FDA (under the brand name Ziana). Salicylic acid, an old standby, has been subjected to few well-designed clinical trials. It is described as a “moderately effective” comedolytic agent to be prescribed, generally, for patients who cannot tolerate topical retinoids.
While a number of systemic antibiotics have been used widely for years and appear to be safe and effective for acne management, bacterial resistance is of increasing concern. This led the Guidelines work group to opine that “patients with less severe forms of acne should not be treated with oral antibiotics, and where possible, the duration of such therapy should be limited.”
The extent of lesions is less important than their type, notes Dr. Van Voorhees. “The criterion for systemic antibiotics is the presence of inflammatory, rather than comedonal, acne.”
Although the literature is inconclusive on the subject, the Guidelines panel suggests that among commonly used agents, minocycline and doxycycline are more effective than tetracycline. Erythromycin is also effective, but it is apparently associated with higher rates of bacterial resistance; its use, the authors propose, should be reserved for patients in whom tetracyclines are contraindicated, such as pregnant women and children younger than 8 years.
The first oral antibiotic to receive FDA approval as first-line treatment for acne, a long-acting formulation of minocycline (Solodyn), became available after the Guidelines were written.