PracticalDermatology

It is estimated that more than half of the US population will consist of non-Caucasians by 2045. As the US population becomes increasingly racially and ethnically diverse, it is necessary to understand how skin diseases manifest differently across skin types. It is also important to educate skin of color patients about skin diseases, as well as the treatment options available to combat disparities in health care.

Caucasian patients comprise a majority of the more than 8 million Americans living with psoriasis. Though the disease is less prevalent among people with skin of color, recent studies show that it is not as uncommon as previously believed. Psoriasis affects 3.6 percent of Caucasians, 1.9 percent of African Americans, and 1.6 percent of Hispanics.¹ Numerous factors may be responsible for the lower reported rates of psoriasis in minority populations, from genetic differences to disparities in access to dermatologists. While psoriasis has been extensively studied in white skin, there are far fewer studies regarding the effects of the disease in skin of color. Lack of general information about pathology and symptoms may also contribute to decreased awareness among patients from minority populations. A 2020 content analysis was conducted on televised direct-to-consumer advertisements for psoriasis. During a two-week period, researchers found that 92.6 percent of the characters depicted as psoriasis patients were Caucasian, while 6.2 percent were Black and 1.2 percent were Asian. The ads contained limited factual information about the disease and did not demonstrate a clear presentation of symptoms in the main characters. This study suggested that patients of color were unlikely to see themselves represented in such ads and therefore may not recognize that psoriasis can affect them, nor would they likely request the advertised treatment from their medical providers.²

Because the signs and symptoms of psoriasis are often presented for Caucasian skin, it can be challenging to diagnose the disease in various skin types. Dermatologists are trained to recognize “classic” psoriasis symptoms in white skin: red or pink erythematous plaques covered with thick silvery scales. Even within the same population, patients may present with distinct clinical manifestations of the disease. In skin of color, psoriasis plaques can present in a range of colors not limited to red tones, and the erythema is often less conspicuous. In Hispanic patients, plaques may appear as salmon-colored patches covered with silvery white scales. Asian patients may have violaceous plaques, and African American patients may have violaceous or dark brown patches with grey scales. The plaques typically resolve with residual dyspigmentation, but can take three to 12 months to disappear, depending on the severity of the disease and the anatomic location of the plaques.¹ Due to the variety in erythema coloration, dyspigmentation can be mistaken for active inflammation or vice versa. Furthermore, residual hyperpigmentation or hypopigmentation that occurs when psoriasis plaques heal is a unique challenge in patients with darker skin types. Post-inflammatory dyspigmentation can also have tremendous psychosocial consequences and is one of the most common reasons individuals with dark skin types visit a dermatologist.

Psoriasis shares overlapping morphological features with other papulosquamous disorders, and patients with skin of color can be misdiagnosed with these clinical mimickers. At first glance, psoriatic plaques may resemble fungal skin infections, lichen planus, cutaneous lupus, discoid lupus, eczema, or sarcoidosis. Skin of color patients can also develop more severe cases of psoriasis, with thicker hyperkeratotic lesions and more extensive skin involvement.³ Asian patients are found to have the highest percentage of affected body surface area (BSA, 41 percent) while Caucasians have the lowest BSA (29 percent).⁴

Treating Psoriasis in Across Skin Types: Challenges and Concerns

Traditional therapies and cultural practices could potentially worsen psoriasis or contribute to post-inflammatory dyspigmentation. Traditional Asian therapeutic methods, like cupping or coining, results in patches of skin irritation that may mask erythema. Herbal medicines may actually have drug interactions with prescribed medications. Scalp psoriasis is often more severe in women with Afro-textured hair who may tolerate long intervals between hair washings.

A few common identifying characteristics of psoriasis include nail involvement, sharply demarcated plaques, and involvement of typical anatomic areas like the scalp, extensor surfaces, palms, soles, and intergluteal cleft.¹

Biologics have proven to be a safe and effective treatment for moderate to severe psoriasis. However, patients in minority groups are less likely than Caucasians to be prescribed biologics. A 2019 study found that African American patients who were biologic-naive displayed less familiarity with self-injections, were more likely to have an aversion to needles, and showed greater concern about potential adverse effects of the medication.⁵ The patients studied were also unfamiliar with other psoriasis therapies, such as oral medications. Phototherapy is another efficacious treatment, but patients with dark skin tones may require higher doses to avoid under-treatment. This method may increase hyperpigmentation, which could deter patients from continuing their therapy.¹

Treatment of plaques with topical corticosteroids or over-the-counter creams can be used in conjunction with biologics or other systemic medications. Patients with thicker lesions will need medications of higher potency. Some regimens for scalp psoriasis may not be compatible with the patients’ hair care practices and cultural preferences. For example, daily hair washing with a medicated shampoo can be an effective treatment, but is not a suitable option for African Americans if their hair type is prone to breakage and dryness. Protective hairstyles like braids might also prevent patients from washing their hair that often. As an alternative, patients are usually receptive to topical formulations that can spread and absorb easily (such as oils or oil-based suspensions, lotions, or emollient foams).

Inclusive Care

Diversification is inevitable, and as the population continues to change it is necessary for medicine to be inclusive. Understanding how skin diseases present differently in patients of all racial and ethnic backgrounds and knowing the most appropriate treatments is important so that every patient receives safe and effective care.

1. 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.

2. Holmes A, Williams C, Wang S, Barg FK, Takeshita J. Content analysis of psoriasis and eczema direct-to-consumer advertisements. Cutis. 2020 Sep;106(3):147-150. doi: 10.12788/cutis.0070. PMID: 33104118.

3. Bilyj, B., 2021. Treating Skin of Color with Psoriasis. [online] Psoriasis.org. Available at: <https://www.psoriasis.org/advance/treating-skin-of-color/> [Accessed 11 March 2021].

4. 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. Journal of Drugs in Dermatology : JDD. 2011 Aug;10(8):866-872.

5. Takeshita J, Eriksen WT, Raziano VT, Bocage C, Hur L, Shah RV, Gelfand JM, Barg FK. Racial Differences in Perceptions of Psoriasis Therapies: Implications for Racial Disparities in Psoriasis Treatment. J Invest Dermatol. 2019 Aug;139(8):1672-1679.e1. doi: 10.1016/j.jid.2018.12.032. Epub 2019 Feb 6. PMID: 30738054; PMCID: PMC6650313.