Identifying psoriasis in richly pigmented skin
Understanding the differences in clinical presentation and morphology, driven by structural and functional skin differences, is key for physicians (1,600 words, 8 minutes)
Evidence is growing in the literature on differences in the incidence, clinical presentation, and morphology of psoriasis among populations with darker skin tones, driven by structural and functional differences in the skin.
This was a topic addressed by Dr. Rachel Asiniwasis during a presentation at the 9th annual Skin Spectrum Summit.
Dr. Asiniwasis is the founder and director of Origins Dermatology in Regina. Since 2015, she and her small team have expanded to service several remote and northern First Nations communities around Saskatchewan through a combination of in-person and teledermatology clinics.
“Looking at differences in psoriasis based on skin of colour compared to lighter skin tones, we know that in patients with more richly pigmented skin types psoriasis is often characterized by much less distinguishable erythema,” said Dr. Asiniwasis. “If these patients have a richly pigmented layer over their skin, the erythema might not be as visible. That's something physicians need to take into account.”
These skin types also have an increased risk of hyperpigmentation with active disease, post-inflammatory hyperpigmentation, and differences in the appearance of psoriatic plaques, she said. This is important for research as well, as many scales such as the Psoriasis Area and Severity Index (PASI) weigh erythema strongly when determining the severity of a patient’s disease.
Colour changes from active psoriasis in darker skin types can be mistaken for post-inflammatory hyperpigmentation, Dr. Asiniwasis said. That means it is important to not rely solely on visual presentation for diagnosis.
“We don't want to under-diagnose psoriasis because then it can progress and become more moderate to severe,” she said. “So I always like to ask the patients about inflammatory symptoms. Are they itching, do they have painful swelling.”
She noted that recent studies have been looking specifically at skin of colour sub-populations with psoriasis.
“I think this is a great thing. An example of this is the VISIBLE study.”
VISIBLE, which is still ongoing, is a prospective, large-scale, randomized-controlled trial conducted to measure psoriasis clearance and other outcomes with the IL-23 inhibitor guselkumab in patients across all skin tones with moderate to severe plaque psoriasis and scalp psoriasis.
“This is opening up an exciting new time in medicine and dermatology,” Dr. Asiniwasis said.
Bottom line: Structural and functional differences in darker skin types result in differences in psoriasis presentation. Physicians should not rely solely on erythema to assess whether psoriasis is currently active in these patients and should ask patients questions about other symptoms of active inflammation. More research is being conducted that will aid in the understanding of the presentation and behaviour of psoriasis across all skin types.
From the literature on psoriasis in skin of colour
Factors associated with quality of life in Chinese people with psoriasis: A cross-sectional study
In this paper, researchers surveyed 185 people with psoriasis to assess their sociodemographic status, disease-related information, psychosocial status, and quality of life. They used multiple stepwise regression and path analysis to study the factors associated with quality of life among Chinese people with psoriasis and to analyze the relationship between those factors.
The survey results showed that the presence of anxiety or depression, lesion area, sleep disorders, psychosocial adaptation, and sex could jointly predict 62.1% of the variance in quality of life among Chinese people with psoriasis.
Researchers established a path model for five variables, based on previous theories and the existing literature. Four internal variables could be effectively explained. The values of the explanatory variables were: quality of life 62.1%, anxiety or depression 71.8%, sleep disorders 44.0%, and psychosocial adaptation 66.9%. The path analysis confirmed that nine paths were consistent with the predicted path, and three paths were not confirmed.
The authors conclude that to improve the quality of life among Chinese people with psoriasis, attention should be given to the presence of anxiety or depression, lesion area, sleep disorders, psychosocial adaptation and sex differences.
Black and male children have an increased risk of palmoplantar psoriasis compared to White children
Researchers conducted a retrospective chart review of 332 pediatric psoriasis patients seen at a single academic institution from 2012 to 2022 and examined risk factors associated with palmoplantar psoriasis.
They found Black patients had a 6.386-fold increase in the odds of having palmoplantar psoriasis compared to White patients. As well, males had a 2.241-fold increase in the odds of having the condition.
Black and Hispanic or Latino patients displayed a higher prevalence of nail and palm/sole involvement (p<0.0001), while White patients exhibited more scalp involvement (p=0.04).
The authors conclude their findings show the importance of considering the diagnosis of palmoplantar psoriasis in Black male patients based on its demographic prevalence, which may in turn impact clinical care for these patients.
Safety and efficacy of ixekizumab in Chinese adults with moderate-to-severe plaque psoriasis: A prospective, multicenter, observational study
Investigators enrolled adults 18 years of age and older with moderate-to-severe plaque psoriasis who had been prescribed ixekizumab in routine clinical practice in a post-marketing study. The primary endpoint was the safety of ixekizumab at week 12. Researchers evaluated treatment effectiveness based on the Psoriasis Area and Severity Index (PASI). They assessed the Dermatology Life Quality Index (DLQI) as a secondary endpoint.
Of 666 enrolled patients, 663 were included in the safety analysis and 612 in the effectiveness analysis.
Some 42.7% of patients reported at least one adverse event, most of which were mild (242/283, 85.5%), and 32.7% (217/663) of patients reported AEs related to study treatment.
The most frequently reported AEs were injection site reactions.
The authors note that AEs led to discontinuation in five patients (0.8%). Only three patients had a serious AE. They found a mean reduction from baseline in PASI score of 10.79±9.55 at week two and 16.80±12.15 at week 12. At week two, 63.7% of patients achieved PASI 50. At week 12, 93.2%, 77.4%, and 45.1% of patients achieved PASI 75, PASI 90, and PASI 100, respectively.
For DLQI, the mean reduction from baseline was 5.91±6.27 at week two and 9.76±7.16 at week 12. DLQI 0/1 was achieved by 19.8% and 59.9% of patients at week two and 12, respectively.
No racial differences found in access to biologics: A population-based study of psoriasis patients in the United States
This population-based study examined data on U.S. psoriasis patients using the 2003 to 2018 Medical Expenditure Panel Survey (MEPS).
Among 31,525,500 adults and children with psoriasis, 3,026,578 (9.6%) were on biologics. Among psoriasis patients, 27,464,864 (87.1%) self-identified as White, 2,033,802 (6.5%) self-identified as Black, 1,173,435 (3.7%) self-identified as Asian or Pacific Islander, and 853,399 (2.7%) self-identified as other races. Among those on biologics, 2,778,239 (91.8%) self-identified as White, 84,971 (2.8%) identified as Black, 89,452 (3.0%) self-identified as Asian or Pacific Islander, and 73,917 (2.4%) self-identified as other races.
The researchers note statistical analysis revealed no significant differences in biologic access between Whites and non-Whites after adjusting for sociodemographic factors including insurance status (odds ratio (OR) for Blacks: 0.347 [0.118, 1.021], P=0.055; OR for Asians: 0.616 [0.240, 1.579], P=0.311; OR for other races: 0.850 [0.216, 3.336], p=0.814).
In their conclusion, the authors say the results suggest that race alone is not independently associated with access to biologics among adult U.S. psoriasis patients. They say additional studies are necessary to evaluate factors independently associated with biologics access among adults and children with psoriasis in the U.S.
VIDEO: Pitfalls in diagnosis and phenotypic differences related to skin of colour | Mohammad Huq, MBBS. DDSc
In a video from the International Psoriasis Council, Dr. Mohammad Samiul Huq, a consulting dermatologist in Dhaka, Bangladesh, discusses the differences in diagnosing psoriatic disease in patients with skin of colour, and the challenges physicians face making these diagnoses.
At the intersection of skin and society
On Oct. 26, 2023, Ontario’s Human Rights Commission recognized caste-based discrimination for the first time last week, publishing an official policy position on how to address the issue under the province's human rights code, reports CBC News.
According to the news outlet, the policy document tells organizations covered by the Ontario Human Rights Code, including employers, housing providers, facilities and unions, and trade or professional associations, that they have an obligation to investigate possible cases of caste-based discrimination.
“Organizations must respond to and investigate claims of caste-based discrimination, and remedy situations when discrimination is found. They should have a human rights complaint procedure in place and could also recognize caste-based discrimination in a corporate human rights policy,” the policy says.
In the document, the commission defines caste as a hierarchy that "determines a person or group's social class or standing, rooted in their ancestry and underlying notions of 'purity' and 'pollution.'"
An example of a caste system the article mentions is the Indian one that historically divided people into four main sub-communities based on ancestry: Brahmins, Kshatriyas, Vaishyas, and Shudras. The four main castes are further divided into 3,000 castes and 25,000 sub-castes.
The CBC notes that some family names are traditionally associated with certain castes, and members of some castes such as the Dalit are considered outcasts.
Vijay Puli, the co-founder of the South Asian Dalit Adivasi Network, told the CBC the move has been a long time coming and that he’s been campaigning for the commission to address caste discrimination for over six years.
“I feel very happy that our voice is being acknowledged in Canadian society,” said Puli.
“It’s the first time we're seeing this kind of progressive step,” he said, adding he’d now like to see policies created by legislators across the country.
Nov. 14 is World Diabetes Day
Nov. 18 to 24 is World Antimicrobial Resistance Awareness Week
Something to think about in the week ahead. . .
—William Lyon Phelps, U.S. educator, 1865 to 1943
Skin Spectrum Weekly will preview some of the informative talks planned for the 2023 Indigenous Skin Spectrum Summit, which will be held virtually on Nov. 25. You can register for free by clicking the link below.
There is still time to register for the 2023 Indigenous Skin Spectrum Summit. First held in 2021, the Indigenous Skin Spectrum Summit is a special session of the Skin Spectrum Summit addressing specific challenges in treating Canada’s Indigenous community. This year’s virtual meeting will be held on November 25, 2023. Register for free at the following link:
If you like Skin Spectrum Weekly, why not check out Chronicle’s other publications, podcasts, and portal?
Established in 1995, The Chronicle of Skin & Allergy is a scientific newspaper providing news and information on practical therapeutics and clinical progress in dermatologic medicine. The latest issue features:
Drs. Irina Turchin (Fredericton, N.B.), Ron Vender (Hamilton, Ont.), and Ashley O’Toole (Peterborough, Ont.) discuss advances in psoriasis treatment.
Dr. Joel DeKoven (Toronto) details the most common contact allergens based on North American Contact Dermatitis Group data.
An essay from Dr. Fabian Rodriguez-Bolanosi (Toronto) submitted to the 2022 Dermatology Industry Taskforce on Inclusion, Diversity and Equity (DiTiDE) short essay contest. Dr. Rodriguez-Bolanosi wrote about his experience working with Black women in the hair clinic.
Plus regular features, including the popular column “Vender on Psoriasis” by dermatologist Dr. Ron Vender
Read a recent digital edition of The Chronicle of Skin & Allergy here. To apply for a complimentary* subscription or to receive a sample copy, please email firstname.lastname@example.org with your contact information.
The Women in Dermatology e-newsletter updates new findings concerning dermatologic issues that affect women and the female dermatologists who care for them. Read the current issue here.
Season two of the Yadav on Acne podcast with Dr. Geeta Yadav has launched. Listen to the new season here. In episode four, Dr. Yadav gives insights into the correlation between vitamin D deficiency and acne, inflammatory factors, and whether the Western diet contributes to acne severity.
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