Addressing underdiagnosis, underrepresentation, and undertreatment in skin of color patients with psoriasis.
Although data and expertise regarding psoriasis in skin of color (SOC) continue to grow, patients of color remain underdiagnosed, underrepresented in clinical trials, and often unable to access dermatologic care. Addressing these inequities requires broadening the scope of educational materials, raising awareness among communities of color, and expanding outreach from clinical-trial sponsors and investigators, an expert tells Dermatology Times.
Epidemiology and presentation
“The bottom line is that there is underrepresentation of nonwhite racial ethnic groups in psoriasis studies,” says Andrew Alexis, MD, MPH. He is Vice-Chair for Diversity and Inclusion in the Department of Dermatology and a dermatologist at the Center for Diverse Skin Complexions at Weill Cornell Medicine in New York.
Underrepresentation fuels misconceptions and misrepresentations. Historically, says Alexis, the prevalence of psoriasis in nonwhite racial/ethnic groups has been thought to be low, particularly among people of African descent. However, he says, more recent data have shown that psoriasis is hardly rare among populations of color. A study published in 2014 revealed prevalence rates of 3.6% 1.9%, and 1.6%, respectively, among whites, African Americans, and Hispanics.1 A subsequent analysis showed a rate of 3.1% among nonwhite, non-Hispanic groups, 2.5% among Asian Americans, 1.9% among Hispanic Americans, and 1.5% among African Americans.2
“There’s a chance that these figures are still underreported,” says Alexis, “because psoriasis may be underdiagnosed in populations of color.3” One contributor to this situation, he says, is disparities in access to dermatologic care, which have been well documented.4 Disparities in access also may explain the tendency for greater psoriasis severity at diagnosis in black and Latino patients, he says.
“The erythema that is characteristic of psoriasis may appear somewhat differently in the background of melanin-rich skin,” adds Alexis. In Fitzpatrick types V and VI, he explains, background pigmentation can make erythematous psoriasis plaques appear violaceous, dark brown, reddish-brown, or gray. Morphologically, East Asian patients have been reported to have a tendency toward smaller, less widespread plaques than do Caucasian patients, despite higher expression of interleukin (IL)-17 and IL-17A-regulated pro-inflammatory cytokines.5
Regardless of race or ethnicity, adds Alexis, the hypo- or hyperpigmentation left behind after psoriatic lesions resolve can last weeks to months and bother patients as much as psoriasis itself. Studies show that psoriasis imposes a higher psychosocial burden, and greater quality-of-life (QOL) impairment, for patients of color.6,7 Although reasons for these differences are not entirely clear, says Alexis, they may include pigmentary alterations, cultural sensitivities, and perceptions of disease. Cultural biases also may contribute to observed racial/ethnic differences in Dermatology Life Quality Index (DLQI) scores,8 which he says is an area that warrants further study.
Diagnosis and treatment
Differential diagnosis of scaly psoriatic plaques also may prove more challenging in SOC, Alexis says. Specifically, features of sarcoidosis, cutaneous T-cell lymphoma, hypertrophic discoid lupus, and lichen planus, all of which occur more commonly in populations of African descent, can overlap with those of psoriasis. “Being aware of this differential diagnosis and having approaches to arrive at the accurate diagnosis are the key recommendations to improve outcomes.”
Recommended approaches involve examining the whole patient, focusing on lesion distribution, color, and morphology. For example, involvement of the scalp, nails, intergluteal cleft, elbows, and knees suggests psoriasis, whereas lichen planus, which is marked by flat-topped scaly plaques often involving the wrists, also may have distinctive lesions in the oral or genital mucosa.
“As with other inflammatory diseases in skin of color,” says Alexis, “we need to address both the active inflammatory lesions and the postinflammatory sequelae.” In some cases, he says, it is probably acceptable simply to treat the active inflammatory lesions and allow time to resolve the pigmentary changes. “But in many instances, patients would prefer active treatment of hyperpigmentation. Adding topical bleaching agents like hydroquinone or a topical retinoid such as tazarotene to their routine can be helpful.” Alexis suggests waiting until lesions have completely resolved before adding hydroquinone.
“On the other hand,” he says, “tazarotene is not solely a bleaching agent—it’s also a treatment for psoriasis. So tazarotene has the advantage of being able to help treat a psoriatic plaque and manage hyperpigmentation at the same time.”9 In a recent study, fixed-combination halobetasol plus tazarotene achieved 2-point investigator global assessment (IGA) improvements in 41.8% of white participants and 39.3% of Hispanic/Latino participants.10
When treating patients of color with psoriasis, cultural nuances that dermatologists must consider range from traditional beliefs and practices to haircare. In the former area, the belief of many Hispanic patients that blood or organ disease causes skin conditions may lead patients to request additional testing.11
Scalp psoriasis is relatively common regardless of ethnicity but may present more severely in African-American women due to less frequent hair washing—once every week or 2 on average, though the interval could be longer depending on the hair style.12 Rather than recommending a treatment that requires more frequent washing than a patient’s hairstyle warrants, Alexis may recommend a once-weekly medicated shampoo, plus additional topical therapies that can be left on the scalp. “For example, there are topical corticosteroid solutions or oil-based vehicles that tend to be more compatible for most women of African ancestry who have scalp psoriasis.”
Together, the challenge of weaving topical therapies into patients’ haircare regimens and the impact of scalp psoriasis in some patients of color prompt Alexis to use a lower threshold for systemic therapies in these patients. “For someone with moderate-to-severe scalp psoriasis that’s not responsive to topical therapy, I would consider oral apremilast, for example, or a biologic.” In a phase 2b trial of apremilast in Japanese patients with moderate-to-severe psoriasis, subjects achieved similar results to those of the full population in phase 3 trials.13
Conversely, clinical results and toxicities of methotrexate, acitretin, and cyclosporine may be impacted by genetic polymorphisms that occur at different rates in different racial and ethnic groups.12 Additionally, phototherapy in SOC can temporarily darken both patients’ overall complexions and any PIH they may have. However, says Alexis, patients may accept these changes if appropriately counseled pretreatment.
Regarding biologics, growing evidence shows safety and efficacy for psoriasis across ethnic groups. The EASE study of etanercept (50 mg twice weekly, open label), for example, showed comparable clinical improvements and adverse-event rates among white, black, Hispanic, and Asian patients.8 A subanalysis of 2 pivotal brodalumab trials revealed similar results for patients of all racial and ethnic groups.14
Among Asian patients, studies of adalimumab in Japanese populations have shown results consistent with US phase 3 results.15,16 A study of secukinumab in 441 Chinese patients posted Psoriasis Area and Severity Index (PASI) rates of 97.7% and 87.2% for 300 and 150 mg doses at week 12, with continued safety through 52 weeks.17 Additionally, subanalyses of the ERASURE secukinumab trial showed that Japanese and Korean patients achieved PASI scores commensurate with those of the full population.18,19
However, a growing body of evidence requires dermatologists to consider potential differences in biologic efficacy between ethnic groups. For instance, the phase 3 REVEAL trial of adalimumab showed superior efficacy in white patients versus nonwhite patients, with week 12 PASI scores of 72% versus 63%.20 Pooled data from 4 phase 3 secukinumab studies likewise show that Hispanic subjects were nearly twice as likely to achieve PASI 75 as non-Hispanic participants (odds ratio: 1.97).21
While ustekinumab has demonstrated efficacy in treating Taiwanese, Korean, Japanese, and Chinese patients with psoriasis, Chinese patients treated with the 45 mg dose achieved the greatest numeric improvement.22 A subanalysis of the VOYAGE 1 and 2 guselkumab trials showed that this drug outperformed adalimumab at week 24 in white and Asian patients, but not black patients, possibly due to the small number of black patients included (guselkumab n = 12).23
Access and inclusion
Performing studies like the foregoing remains very important, says Alexis. “But what would be even better would be studies that enroll a more diverse patient population. Then these subpopulation analyses would be more robust.”
Solving this problem, he says, begins with carefully considering local demographics when selecting investigator sites for large clinical trials. “Next would be encouraging investigators to inform their communities broadly about studies that they’re conducting and including populations that historically have had less access to information on clinical trials.”
The latter amounts to a call to action upon study sponsors and investigators to make efforts to inform and enroll integral and diverse patient populations, Alexis says. “It’s recognized as a concern within organizations such as the Skin of Color Society (of which he is Scientific Committee Co-Chair).” Efforts by the Society to help narrow the representation gap in all dermatologic disease states are in planning phases, he adds.
For the future, says Alexis, the specialty should continue in the direction of improving educational resources so that examples of how psoriasis presents across the spectrum of diverse populations and skin complexions are represented, and practitioners are better able to recognize and diagnose psoriasis in subpopulations. Simultaneously, he advised raising awareness in the community that psoriasis is by no means limited to individuals of European ancestry. “That could contribute to earlier diagnosis and optimal treatment for patients of color with psoriasis.”
1. Rachakonda TD, Schupp CW, Armstrong AW. Psoriasis prevalence among adults in the United States. J Am Acad Dermatol. 2014;70(3):512-516.
2. Armstrong AW, Mehta MD, Schupp CW, Gondo GC, Bell SJ, Griffiths CEM. Psoriasis prevalence in adults in the United States [published online ahead of print, 2021 Jun 30]. JAMA Dermatol. 2021;10.1001/jamadermatol.2021.2007. doi:10.1001/jamadermatol.2021.2007
3. Kurd SK, Gelfand JM. The prevalence of previously diagnosed and undiagnosed psoriasis in US adults: results from NHANES 2003-2004 [published correction appears in J Am Acad Dermatol. 2009;61(3):507]. J Am Acad Dermatol. 2009;60(2):218-224.
4. Fischer AH, Shin DB, Gelfand JM, Takeshita J. Health care utilization for psoriasis in the United States differs by race: an analysis of the 2001-2013 Medical Expenditure Panel Surveys. J Am Acad Dermatol. 2018;78(1):200-203.
5. Kim J, Oh CH, Jeon J, et al. Molecular phenotyping small (Asian) versus large (Western) plaque psoriasis shows common activation of IL-17 pathway genes but different regulatory gene sets. J Invest Dermatol. 2016;136(1):161-172.
6. Alexis AF, Blackcloud P. Psoriasis in skin of color: epidemiology, genetics, clinical presentation, and treatment nuances. J Clin Aesthet Dermatol. 2014;7(11):16-24.
7. Kerr GS, Qaiyumi S, Richards J, et al. Psoriasis and psoriatic arthritis in African-American patients--the need to measure disease burden. Clin Rheumatol. 2015;34(10):1753-1759.
8. Shah SK, Arthur A, Yang YC, Stevens S, Alexis AF. A retrospective study to investigate racial and ethnic variations in the treatment of psoriasis with etanercept. J Drugs Dermatol. 2011;10(8):866-72.
9. Desai SR, Alexis AF, Jacobson A. Successful management of a black male with psoriasis and dyspigmentation treated with halobetasol p ropionate 0.01%/tazarotene 0.045% lotion: case report. J Drugs Dermatol. 2020;19(10):1000-1004.
10. Alexis AF, Desai SR, Han G, Jacobson A. Fixed-combination halobetasol propionate and tazarotene lotion for psoriasis in patients with skin of color. J Drugs Dermatol. 2021;20(7):735-744.
11. Moy JA, McKinley-Grant L, Sanchez MR. Cultural aspects in the treatment of patients with skin disease. Dermatol Clin. 2003;21(4):733-742.
12. Kaufman BP, Alexis AF. Psoriasis in skin of color: insights into the epidemiology, clinical presentation, genetics, quality-of-life impact, and treatment of psoriasis in non-white racial/ethnic groups [published correction appears in Am J Clin Dermatol. 2018 Feb 16;]. Am J Clin Dermatol. 2018;19(3):405-423.
13. Ohtsuki M, Okubo Y, Komine M, et al. Apremilast, an oral phosphodiesterase 4 inhibitor, in the treatment of Japanese patients with moderate to severe plaque psoriasis: efficacy, safety and tolerability results from a phase 2b randomized controlled trial. J Dermatol. 2017;44(8):873-884.
14. McMichael A, Desai SR, Qureshi A, Rastogi S, Alexis AF. Efficacy and safety of brodalumab in patients with moderate-to-severe plaque psoriasis and skin of color: results from the pooled AMAGINE-2/-3 randomized trials. Am J Clin Dermatol. 2019;20(2):267-276.
15. Asahina A, Nakagawa H, Etoh T, Ohtsuki M; Adalimumab M04-688 Study Group. Adalimumab in Japanese patients with moderate to severe chronic plaque psoriasis: efficacy and safety results from a phase II/III randomized controlled study. J Dermatol. 2010;37(4):299-310.
16. Asahina A, Torii H, Ohtsuki M, et al. Safety and efficacy of adalimumab treatment in Japanese patients with psoriasis: results of SALSA study. J Dermatol. 2016;43(11):1257-1266.
17. Cai L, Zhang JZ, Yao X, et al. Secukinumab demonstrates high efficacy and a favorable safety profile over 52 weeks in Chinese patients with moderate to severe plaque psoriasis. Chin Med J (Engl). 2020;133(22):2665-2673.
18. Wu NL, Hsu CJ, Sun FJ, Tsai TF. Efficacy and safety of secukinumab in Taiwanese patients with moderate to severe plaque psoriasis: subanalysis from ERASURE phase III study. J Dermatol. 2017;44(10):1129-1137.
19. Ohtsuki M, Morita A, Abe M, et al. Secukinumab efficacy and safety in Japanese patients with moderate-to-severe plaque psoriasis: subanalysis from ERASURE, a randomized, placebo-controlled, phase 3 study. J Dermatol. 2014;41(12):1039-1046.
20. Menter A, Gordon KB, Leonardi CL, Gu Y, Goldblum OM. Efficacy and safety of adalimumab across subgroups of patients with moderate to severe psoriasis. J Am Acad Dermatol. 2010;63(3):448-456.
21. Adsit S, Zaldivar ER, Sofen H, et al. Secukinumab is efficacious and safe in Hispanic patients with moderate-to-severe plaque psoriasis: pooled analysis of four phase 3 trials. Adv Ther. 2017;34(6):1327-1339.
22. Zhu X, Zheng M, Song M, et al. Efficacy and safety of ustekinumab in Chinese patients with moderate to severe plaque-type psoriasis: results from a phase 3 clinical trial (LOTUS). J Drugs Dermatol. 2013;12(2):166-174.
23. Gordon KB, Blauvelt A, Foley P, et al. Efficacy of guselkumab in subpopulations of patients with moderate-to-severe plaque psoriasis: a pooled analysis of the phase III VOYAGE 1 and VOYAGE 2 studies. Br J Dermatol. 2018;178(1):132-139.
Dr. Alexis has been a grant recipient/researcher and consultant for Almirall, Amgen, Bristol Myers Squibb, Galderma, Leo Pharma, Menlo Therapeutics, Novartis, and Valeant (Bausch Health). He also has been a consultant and speaker for Pfizer and Sanofi and Regeneron; a grant recipient/researcher for Arcutis and Cara Therapeutics; a consultant for AbbVie, Allergan, Beiersdorf, Cassiopea, Dermavant, Janssen, L’Oreal, Scientis Pharma, Sol-Gel, VYNE Therapeutics, UCB, and Unilever; and a speaker for AstraZeneca.