When it comes to treating psoriasis in non-white patients, there is a paucity of data on differences in epidemiology, clinical presentation and approaches to treatment.
“Although psoriasis appears to have a lower prevalence in non-white racial ethnic groups, including African Americans, it is by no means an uncommon or rare disease,” says Andrew Alexis, M.D., chair of the department of dermatology and director of the Skin of Color Center at Mount Sinai St. Luke’s and Mount Sinai West in New York City. He spoke on psoriasis at the Skin of Color Seminar Series (SOCSS) in New York City in May.
In fact, a recent study found a 1.9% prevalence rate of psoriasis in African Americans.
“This is much more common than previously reported,” Dr. Alexis tells Dermatology Times.
The clinical presentation of psoriasis in darker skinned individuals can vary, based primarily on the visual appearance. For example, because of the background melanin pigmentation, “the erythema may look more violaceous, hyperpigmented or dark brown or gray,” Dr. Alexis says. “Therefore, one has to train the eye to detect psoriasis-related erythema in darker skin types.”
Clues of psoriasis include the quality of the scale, the anatomic distribution and associated features.
There are scenarios, though, where a biopsy is needed to confirm the diagnosis of psoriasis.
“I find this is more frequent in darker skin types,” Dr. Alexis says.
For instance, patients with skin type VI may present with violaceous, gray, or hyperchromic scaly plaques without appreciable erythema.
“In these patients, it may be difficult to distinguish the psoriasis from lichen planus, cutaneous T-cell lymphoma or sarcoidosis in some cases,” Dr. Alexis says.
For treatment, a few studies have looked at potential racial ethnic differences in safety and efficacy.
“Once such study1 found comparable safety measures and efficacy outcome measures for the injectable TNF antagonist, etanercept (Enbrel, Amgen)” Dr. Alexis says.
However, in the above study from the Journal of Drugs in Dermatology in 2011, racial/ethnic differences in quality-of-life impact were observed. As measured by the Dermatology Quality of Life Index (DLQI), “baseline quality of life was actually worse in African American and Hispanic/Latino patients compared to Caucasians,” Dr. Alexis says.
More recently, Dr. Alexis was co-author of a poster at this year’s SOCSS that evaluated the safety and efficacy of the recently approved biologic agent brodalumab (Siliq, Valeant), for which there was no significant racial or ethnic differences in safety or efficacy.2
“Studies like this are important to understand whether there are any potential differences in safety and efficacy, particularly with biologics that are so specific in their target,” Dr. Alexis says. “Fortunately, we have not seen any significant differences with the studies that have been conducted thus far.”