Treating acne, rosacea in patients of color requires attention to inflammation

Miami Beach, Fla. - Recent developments regarding acne and rosacea in skin of color include studies showing that combination topical products for acne appear safe in this population, and the fact that rosacea is perhaps more prevalent than many might expect.

In the former area, says Valerie D. Callender, M.D., some dermatologists and patients have wondered whether newer topical combination products for acne increase irritation in darker skin types. Dr. Callender, who spoke at the annual meeting of the American Academy of Dermatology, is associate professor of dermatology, Howard University College of Medicine, and a private practitioner based in the Washington metropolitan area.

In this regard, she says that when it comes to dual-combination products, “We’ve shown that the ingredients are safe when used as monotherapy.” More recently, she says, research has shown that when one combines agents, “There’s no increased risk of irritation.”

Combination comparisons

In fact, a meta-analysis of three pivotal clinical trials involving benzoyl peroxide-adapalene combination treatments showed that these products tend to cause less erythema, scaling and dryness (P<0.001 in all three analyses) in skin types IV through VI than in skin types I through III (Callender VD, Preston N, Osborn C, et al. J Clin Aesthet Dermatol. 2010;3(8):15-19). Other studies have found no differences between these populations regarding tolerability of the following combinations:

· Clindamycin-benzoyl peroxide (Callender VD. J Drugs Dermatol. 2012;11(5):643-648);

· Clindamycin-tretinoin (Callender VD, Young CM, Kindred C, Taylor SC. J Clin Aesthet Dermatol. 2012;5(7):25-32).

The tolerability of these newer combination treatments stems largely from their use of water-based vehicles, rather than alcohol, Dr. Callender says.

“Some of the vehicles also contain moisturizers,” she says.

Meanwhile, dermatologists’ understanding of the role of inflammation in all acne is growing. Historically, she explains, “We’ve thought about the acne lesion being either inflammatory or noninflammatory. But the new theory is that all lesions are inflammatory - that’s how acne starts.”

In one study, investigators biopsied apparently noninflammatory comedones in African-American patients. “But when the investigators looked at these lesions histologically, they found marked inflammation in the skin (Halder RM, Holmes YC, Bridgeman-Shah S, Kligman AM. Invest Dermatol. 1996;106:888; Abstract 495). So inflammatory lesions can include not just the papules, pustules, cysts and nodules, but also the comedones. This increases the risk of postinflammatory hyperpigmentation in patients of color.”

Moreover, she says that when treating patients of color with acne, “We must address the hyperpigmentation simultaneously. That’s more important to the patient than the acne,” which some of them may not know is causing the hyperpigmentation. “If you don’t tell the patient you’re treating the hyperpigmentation as well as the acne, the patient will not follow your regimen, because that’s what they’re complaining of - the dark spots.” To that end, she recommends initiating topical retinoid treatment at the first visit for all patients with acne because topical retinoids attack acne and PIH simultaneously.

Use of hydroquinone

As for hydroquinone, she says that in the United States, exogenous ochronosis tends to result from continuous usage of over-the-counter hydroquinone for a decade or more. “It’s very difficult to treat because you can’t use hydroquinone for exogenous ochronosis.” Several case reports explore the use of a 1,064 nm Q-switched Nd:YAG laser (at low settings) for this purpose, she says, but results in darker skin types are mixed.

Regarding rosacea, Dr. Callender adds, “The literature states that rosacea occurs mainly in Caucasians of European descent. There are very few case reports and very little discussion about patients of color. However, we do know that it exists in African-American, Hispanic, Indian and Asian populations. And it’s important for dermatologists to know that. We need to publish more on rosacea in skin of color. Until then, we must teach each other that it does exist, and we must look for it” in this population.

In this regard, “Erythema and flushing are not readily seen in individuals with darker skin. So as dermatologists, we must be more suspicious and look for other signs.” Whereas one must watch for postinflammatory hyperpigmentation (PIH) in patients of color with acne, she explains, “In patients with darker skin types and rosacea, we see more hypopigmentation.” The pathophysiology and treatment of rosacea are essentially the same regardless of skin type, Dr. Callender says, except that lasers and light-based devices have been shown to cause dyspigmentation in darker skin types.

Disclosures: Dr. Callender has been a consultant and speaker for Allergan, Galderma and Valeant, and a clinical investigator for Allergan, Galderma, Suneva and Medicis.