- Monday, July 31, 2023
- Allison Truong, MD, FAAD
- Disease Severity, Expert Insights, Research, Treatment, Quality of Life, Diagnosis
THE 101
- Psoriasis is a common, chronic skin condition affecting many people worldwide.
- Current therapies for psoriasis include topicals, phototherapy, oral agents, and injectable systemics.
- Existing evidence suggests no signals for concern regarding efficacy and safety for use in all diverse ethnic groups.
- The decision on which treatment should be used depends on individual patient-related factors, including disease severity, comorbidities, concurrent medications, prior treatment responses, quality of life impairments, patient preferences, and insurance coverage. In addition to these factors, there are certain practical implications of treating psoriasis in patients of skin of color that should also be considered.
Topical Therapies for Psoriasis: Practical Implications for Skin of Color
For mild or limited disease, topical therapies are the first line. Topical therapies include topical corticosteroids, vitamin D analogs, retinoids, calcineurin inhibitors, combination therapies (i.e. corticosteroid-vitamin D analogs), and newer agents, including roflumilast and tapinarof creams. Localized treatment with targeted phototherapy or excimer laser may also be employed. For skin of color patients, consider the higher risk of hypo- or hyper-pigmentation in patients with long-term use of high-potency topical steroids and consider transitioning to nonsteroid agents in the maintenance phase once acute inflammation has improved.1 For scalp psoriasis, the choice of vehicle (oils, lotions, foams, shampoos) and frequency of application should be discussed with patients, as cultural hair practices play a role in the daily life of patients of African descent.1 The ease and practicality of the therapies give yield to higher patient compliance, and understanding these cultural nuances will help patients achieve better clinical outcomes.1
Phototherapy and Systemic Agents: Optimizing Treatment for Severe Psoriasis in Skin of Color
Phototherapy, oral agents, and injectable systemic agents are utilized for severe disease. In-office or at-home phototherapy with narrowband UVB, psoralen UVA (PUVA), or combination treatments with light therapy and oral systemic agents may be used as first-line in those with risk factors that preclude other systemics.
Due to darker skin phototypes, higher initial doses are required for phototherapy for skin of color patients. Studies in psoriasis in Asian and Indian children have proven the safety and efficacy of narrowband UVB and PUVA in darker skin patients.3,9 Given that phototherapy may often lead to darker skin tones, certain cultures have preferred ideals of lighter complexions as a form of beauty.1 Thus, some patients may prefer other treatment modalities due to the fear of this expected side effect.1 Fortunately, patients may be reassured that the skin tanning will resolve in time once remission is achieved.
Oral Agents for Psoriasis: Treatment Response and Side Effect Profiles in Non-White Patients
Oral agents include methotrexate, acitretin, cyclosporine, apremilast, tofacitinib, and newly approved deucravacitinib for psoriasis and upadacitinib for psoriatic arthritis. There are some observed differences in treatment responses and side effect profiles for oral agents in white and non-white individuals in psoriasis patients.5 Some of these differences may be explained by genetic differences in ethnic groups. For example, a study in Asia of South Indian Tamils showed superior responses to methotrexate in patients with HLA-Cw*06 and FOXP3 polymorphisms.4 In contrast, for unknown mechanisms, in patients of Asian descent compared to North American, European, and Latin American, tofacitinib appears to have a three times higher risk of herpes zoster.7,8,11 Further studies need to be performed to further understand which medications may have more favorable results with fewer side effects in different ethnic populations to lessen the burden of this disease.
Biologic Agents: Efficacy and Safety in Psoriasis Patients of Different Ethnicities
Biologic agents for psoriasis and/or psoriatic arthritis include anti-tumor necrosis factor: etanercept, infliximab, adalimumab, certolizumab, golimumab; anti-IL17: secukinumab, ixekizumab, brodalumab; anti-12/23: ustekinumab; anti-IL23: guselkumab, tildrakizumab, risankizumab; anti-CTLA4: abatacept. Biosimilars are also available for use in lieu of biologics.
Current available retrospective analyses and subanalyses show differences in the efficacy of certain biologics over others in different ethnic groups. In Asian populations, biologic agents in Japanese groups appear to have superior efficacy in some studies, such as secukinumab, brodalumab, ixekizumab, and tofacitinib.5 It is postulated that Asian clinical trial patients have lower body weight, fewer psoriatic arthritis, shorter disease duration, and higher baseline severity compared to White subjects which may play a role in efficacy.5 Genetic differences between ethnic groups for biologics may also play a role as it does for oral agents as well. HLA polymorphisms have been associated with higher response to biologic treatments, as in the studies study in Chinese and White psoriasis patients with HLA-Cw*06 having a greater, faster, and longer duration of response to ustekinumab.8 Prior psoriasis studies had limited numbers of non-white participants through the years, with phase III pivotal trials for biologic treatments enrolling 67-95.4% white participants.2 More recent studies have been completed and are currently ongoing to include diverse populations in clinical trials, given the potential for pharmacogenomic differences that may influence safety and efficacy.
Advancements in Psoriasis Treatment for Skin of Color: Future Perspectives
As newer topicals and systemics in oral or injectable forms continue to be developed, more treatments will be added to the armamentarium for psoriasis. Given the overall interest in ensuring that patients of skin of color are represented in clinical trials, hopefully, more data will be available to help clinicians provide the most optimal care to patients of all backgrounds.
References
- Psoriasis in Skin of Color: Epidemiology, Genetics, Clinical Presentation, and Treatment Nuances. Alexis AF, Blackcloud P. J Clin Aesthet Dermatol. 2014;7(11):16–24.
- Diversity in Dermatology Clinical Trials. Charrow A, Xia FD, Joyce C, Mostaghimi A. JAMA Dermatol. 2017;153(2):193.
- Narrowband Ultraviolet B Versus Psoralen Plus Ultraviolet A Therapy for Severe Plaque Psoriasis: An Indian Perspective. Chauhan PS, Kaur I, Dogra S, De D, Kanwar AJ. Clin Exp Dermatol. 2011;36(2):169–73.
- Pharmacogenetic Markers to Predict the Clinical Response to Methotrexate in South Indian Tamil Patients with Psoriasis. Indhumathi S, Rajappa M, Chandrashekar L, Ananthanarayanan PH, Thappa DM, Negi VS. Eur J Clin Pharmacol. 2017;73(8): 965–71.
- 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.Kaufman B, Alexis A. Am J Clin Dermatol (2018) 19:405–423.
- Comparison of the Efficacy of Psoralen Ultraviolet A with Narrowband Ultraviolet B Phototherapy for the Treatment of Chronic Plaque Psoriasis in Patients with Skin Types IV and V. Kaur J, Sharma VK, Sethuraman G, Tejasvi T. Clin Exp Dermatol. 2008;33(4):513–5.
- A Review of Clinical Trials of Biologic Agents and Small Molecules for Psoriasis in Asian Subjects. Tsai YC, Tsai TF. G Ital Dermatol Venereol. 2016;151(4):412–31.
- A Systematic Review of Pharmacogenetic Studies on the Response to Biologics in Patients with Psoriasis. van Vugt LJ, van den Reek JMPA, Coenen MJH, de Jong EMGJ. Br J Dermatol. 2018 Jan;178(1):86-94. doi: 10.1111/bjd.15753. Epub 2017 Dec 14. PMID: 28646581.
- Role of Narrowband Ultraviolet B phototherapy in the Treatment of Childhood Psoriasis in Asian Children. Wong Y, Koh MJ, Chong WS. Pediatr Dermatol. 2015;32(5):e221–3.
- Herpes Zoster and Tofacitinib Therapy in Patients with Rheumatoid Arthritis. Winthrop KL, Yamanaka H, Valdez H, Mortensen E, Chew R, Krishnaswami S, et al. Arthritis Rheumatol. 2014;66(10):2675–84.
- The Efficacy and Safety of Tofacitinib in Asian Patients with Moderate to Severe Chronic Plaque Psoriasis: A Phase 3, Randomized, Double-blind, Placebo-controlled Study. Zhang J, Tsai TF, Lee MG, Zheng M, Wang G, Jin H, et al. J Dermatol Sci. 2017;88(1):36–45.
