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Clinical Challenges: Managing Atopic Dermatitis in African Americans

— Diagnosis and treatment of darker skin poses unique issues

Ƶ MedicalToday
An African American man scratching his arm

In the U.S., the prevalence of atopic dermatitis (AD) is higher among African Americans, at almost 20%, compared with European Americans (16%) and Hispanic Americans (8%).

In addition, the prevalence of has been growing over the past 2 decades, with an increasing representation of African-American children being a major contributing factor, noted Jonathan Silverberg, MD, PhD, MPH, of George Washington University School of Medicine and Health Sciences in Washington, D.C.

"The observed differences are likely multifactorial. However, one contributing factor is poor disease control and greater disease persistence in African-American/Black children, which suggests there are racial disparities. As a field, we need to do a better job assessing and managing AD across all patient races and subsets," Silverberg told Ƶ.

The trend may also reflect a growing number of AD diagnoses resulting from increased access to healthcare, said Danny Del Campo, MD, of Chicago Skin Clinic.

"Other factors include environmental and daily habits that ultimately influence the allergic immune response. Excessive bathing is a frequent factor and chronic disruption of the skin barrier is likely a key player in the increased prevalence of AD," Del Campo told Ƶ.

In addition, AD appears to have a more in African-Americans compared with European-American populations, with Black children at about six times greater risk of having severe AD than their white counterparts, according to a longitudinal study.

Importantly, this difference in severity only reached significance after study authors adjusted for erythema score (OR 5.93, 95% CI 1.94-18.12, P=0.002), leading the group to caution that erythema can be a "misleading indicator of severity in Black children. Difficulties of assessment due to skin pigmentation might mean that severe cases are not being detected and appropriately treated."

When assessing patients with darker skin for AD/erythema, don't look for redness, advised Jasmine O. Obioha, MD, of Cedars-Sinai Medical Center in Los Angeles. Active eczema areas in lighter skin are often red in contrast to dark brown or gray in darker skin. Additionally, different forms of eczema are more prevalent in darker skin; for instance, papular eczema, which is characterized by follicular-based lesions that may not be recognizable unless you actually touch the patient and feel warmth and inflammation, she told Ƶ.

In addition to papulation, is more likely to have greater lichenification and pigmentary changes, and to favor extensor surfaces, compared with lighter skin types. Black patients are also more likely to have hyperlinearity of the palms, periorbital dark circles, Dennie-Morgan lines, and prurigo nodularis.

The first step in development of AD -- skin barrier dysfunction -- is influenced by . These well-known contributors to inherent barrier defects, reported in up to 50% of European-American patients with AD, are six times less common in African-American patients, even in those with severe AD.

According to a 2018 study, other in eczema between African-Americans and European-Americans include decreased expression of innate immune, Th1-related, and Th17-related markers in Black patients versus white patients (P<0.05), though there is similar upregulation of Th2- and Th22-related markers in both groups.

Th2- and Th22-related markers, along with serum IgE, were significantly associated with clinical severity on Scoring of Atopic Dermatitis (SCORAD) in African-Americans.

"Our data encourage a personalized medicine approach accounting for phenotype-specific characteristics in future development of targeted therapeutics and clinical trial design for AD," the study authors wrote.

In a post-hoc, placebo-controlled , the interleukin (IL)-4/13 inhibitor dupilumab (Dupixent), the only biologic approved for moderate-to-severe AD, was associated with significant clinical improvement and a favorable benefit-risk profile at week 16 across white, Asian, and Black patient subgroups.

In the Black subgroup (n=128), dupilumab significantly improved Eczema Area and Severity Index (EASI) endpoints and mean changes in the Peak Pruritus Numerical Rating Scale (NRS) and the Dermatology Life Quality Index (DLQI) compared with placebo (P<0.0001), with positive numeric trends favoring dupilumab in all other endpoints.

In an of commonly used outcome measures across different races, ethnicities, and skin tones, Silverberg and co-authors identified "significant differential item functioning between race subgroups for one or more items" on many of these scales.

At the recent Revolutionizing Atopic Dermatitis conference, study authors noted that the Patient-Oriented Eczema Measure (POEM) did seem to correlate similarly with the EASI and DLQI in both white and non-white participants, "which may indicate why this trifecta of instruments is recommended by the HOME [Harmonising Outcome Measures for Eczema] group."

"Although a specific tool for assessing atopic dermatitis in African-Americans does not exist yet, I find the Atopic Dermatitis Control Tool () helpful, as it not only relies on clinician-reported data but also patient-reported experiences," Obioha told Ƶ.

She noted that AD-related pigment changes such as post-inflammatory hyperpigmentation are "a major concern for people of color that should be considered in treatment. This discoloration can last for months to years, even after the eczema is treated."

"It's important to be able to distinguish active eczema from post-inflammatory hyperpigmentation ... to avoid underestimating the response to treatment or inaccurately consider someone a treatment failure," Obioha added.

"Hypopigmentation tends to occur in younger children, patients with dry skin, and those with chronic topical steroid use, while hyperpigmentation can occur with chronic disease. Either way, the pigment change is caused by inflammation in the skin and will resolve once the inflammation is treated. Although it requires some patience, I rarely give AD patients creams to accelerate the return to their normal skin tone because of the risk of skin irritation and reactivating the atopic dermatitis," said Anisha B. Patel, MD, of the University of Texas MD Anderson Cancer Center in Houston, in an interview with Ƶ.

Management of post-inflammatory pigmentary changes often depends on the location on the body and the degree of severity, noted Del Campo.

"Along with frequent moisturizing and sun-protective behaviors, prevention of future flaring of atopic dermatitis is essential to prevent the hyperpigmented areas from becoming worse."

To that end, Patel always sets her patients up with written "maintenance" and "flare" regimens and tries to teach them how to best care for themselves.

Indeed, educating patients on proper skin care is a fundamental step in the treatment of AD that is often overlooked in a busy clinical practice, added Del Campo. He directs patients to the to learn more about proper skin care.

"Many patients take long showers once or twice a day. I stress the importance of limiting bathing/showers to less than 10 minutes, using lukewarm water and hypoallergenic skin cleanser, and applying thick moisturizers as often as possible," he said. "New patients often apply rubbing alcohol for cooling/itch relieving effects, which I explain is making the skin barrier worse. If cold sensation improves itch, I suggest they apply cold moisturizer kept in the refrigerator instead. Lastly, when in doubt, I tell patients to 'treat your skin like you would a newborn baby -- don't use anything you wouldn't put on a newborn baby's skin.'"

  • author['full_name']

    Kate Kneisel is a freelance medical journalist based in Belleville, Ontario.

Disclosures

Silverberg disclosed relationships with AbbVie, Afyx, AOBiome, Arena, Asana, BiomX, Bluefin, Bodewell, Boehringer Ingelheim, Celgene, Dermavant, Dermira, Eli Lilly, Galderma, GlaxoSmithKline, Incyte, Kiniksa, Leo, Luna, Menlo, Novartis, Pfizer, RAPT, Regeneron, and Sanofi-Genzyme.

Del Campo and Obioha reported no disclosures.

Patel disclosed relationships with Novartis, OnQuality, Deciphera, and NanOlogy.