Psoriasis on Black Skin

Psoriasis, an autoimmune skin disease, can look different on Black people and other people of color than on White people. It is sometimes harder to see on darker skin than on lighter skin. It can also be harder to conceal when severe and make those affected feel more self-conscious.

On light skin, psoriasis causes dry, red, itchy patches with silvery scales known as plaques. But, on dark skin, the plaques may be a dark brown or a purplish gray and can be easily confused for other skin conditions.

This article describes how psoriasis differs in people of color as well as conditions psoriasis is commonly mistaken for on Black skin. It also takes a look at some of the nuances involved in the diagnosis and treatment of psoriasis in people with darker skin tones.

How Common Is Psoriasis in Black People?

Psoriasis can affect anyone but is far more common in White people. Comparatively, Black people in the United States are anywhere from two to six times less likely to have psoriasis. Black children are similarly four times less likely than White children to have the disease.

Overall, less than 2% of Black adults in the United States have psoriasis, according to the ongoing National Health and Nutrition Examination Survey (NHANES).

Psoriasis Symptoms on Black Skin

Psoriasis doesn't look the same on dark skin as it does on light skin.

In Black people, there will be a lower risk of erythema (superficial reddening) than what is seen in White people. On the other hand, there will be a higher risk of hyperpigmentation (darker skin discoloration) or hypopigmentation (the lightening of skin) than in White people.

A person with darker skin may feel changes in the skin but not see them when the symptoms are mild. However, when symptoms are severe, they are more likely to have noticeable skin discoloration than what might be seen on lighter skin.

Scalp psoriasis also tends to be more common and severe in Black people. Genetics may play a role as well as washing naturally textured hair less often to prevent hair breakage.

The differences in symptoms can have an extreme emotional impact on Black people with psoriasis. According to a 2014 study in the Journal of Clinical and Aesthetic Dermatology, 72% of minorities said that psoriasis lowered their quality of life compared to only 54% of White respondents. This included feelings of self-consciousness, frustration, helplessness, and anger.

Differences in Causes and Risk Factors

No one knows the exact cause of psoriasis. With that said, a person's genetics is thought to heavily influence their risk for the disease, while environmental factors such as infections, smoking, or air pollution are thought to trigger the onset or recurrence of psoriasis symptoms.

In terms of genetics, studies suggest that some of the genes closely linked to psoriasis affect racial and ethnic groups differently. A surprising number of these genes—known as ERAP1, FBXL19, HLA-C, IFIH1, IL4, IL13 IL23A, IL23R, IL23B, IL28RA, NOS2, NFKBIA, REL, TNAIP3, TNIP1, TRAF3IP2, and TYK2—appears solely linked to people of White European descent.

A rare exception is HLA-Cw6, a gene mutation seen almost twice as often in Black people than in White people. Several others, like LCE3C and LCE3B, are seen in people of European or Asian descent.

Differences in Diagnosis

Because psoriasis can look vastly different in people of color, there is a risk of misdiagnosis. This is because psoriasis on Black skin can mimic other skin conditions, including:

• Acanthosis nigricans: This is a condition commonly seen in people with obesity and diabetes in which dark, thick velvety skin will develop in armpits, groin, and other skin folds.
• Cutaneous lupus erythematosus: This is a skin-related complication of lupus.
• Drug eruptions: Certain drug reactions can cause papulosquamous eruptions characterized by purplish skin with scales.
• Lichen planus: This is an immune-related condition that can cause swelling and irritation of the skin, hair, nails, and mucous membranes.
• Seborrheic dermatitis: This is a common condition that mainly affects the scalp, causing scaly patches, inflamed skin, and stubborn dandruff.

Differences in Psoriasis Treatment

Skin color usually doesn't determine which types of treatment are available for people with psoriasis.

With that said, a person's socioeconomic status may influence their access to certain treatments. This was not only due to the unequal access to medical care in the United States but also to the fact that Black people tend to be less receptive to injectable drugs like Humira or to those they find unfamiliar, according to a 2019 study in the Journal of Investigative Dermatology.

There are also subtle differences in treatment approaches for Black people and other people of color. Among them:

• People with darker skin tones may have thicker psoriatic patches that need more aggressive treatment with higher-potency medications and phototherapy.
• In people with psoriasis hypopigmentation, the ultraviolet (UV) light used in phototherapy can sometimes make the condition worse.
• Because daily hair-washing is not recommended for naturally textured hair or in hair with braids or extensions, topical creams and lotions may be needed instead of medicated shampoos.

Summary

Psoriasis can be harder to detect on the skin of Black people than of White people. Even when symptoms are seen, they can mimic other diseases like acanthosis nigricans, which also causes dark patches of skin. Because of this, psoriasis may not be recognized in Black people until the symptoms are severe and harder to treat.

For reasons that are not entirely clear, Black people also tend to experience worse psoriasis symptoms covering larger areas of skin. They also may not respond as well to certain treatments such as phototherapy and require more aggressive therapies.