Dyschromia, dyspigmentation present unique challenges for skin of color
Patients with skin of color have unique challenges when it comes to treating psoriasis.
Dyschromia and dyspigmentation, a change of color in the skin or nails, can negatively affect individuals with skin of color. Although it is often seen as a cosmetic issue, discoloration of the skin can have long-lasting mental and physical effects.
Healio Psoriatic Disease spoke with Amy J. McMichael, MD, FAAD, professor and chair of the department of dermatology at Wake Forest Baptist Health Sciences and co-chair of the Skin of Color Society Scientific Committee, about the causes of dyschromia and dyspigmentation and how best to treat them.
Q: What are dyschromia and dyspigmentation?
A. Dyschromia is a change in color of the skin or nails. Although not specific to pigmentation, it is usually used to reference abnormality in pigmentation, but it can be a change in color, a loss or increase in pigmentation.
Dyspigmentation refers to an abnormality in the formation or distribution of pigmentation in the skin. It may clinically appear as too much pigmentation (hyperpigmentation) or too little pigmentation (hypopigmentation).
These terms are very close in meaning.
Q: What are the main causes of dyschromia and dyspigmentation?
A. The list of disease processes that cause these changes in the skin are too long to enumerate here. The main thing to understand is that there are primary and secondary diseases of hyperpigmentation as well as hypopigmentation.
Primary disease of hyperpigmentation includes melasma and some congenital skin disorders (nevus spilus, café au lait macules and congenital dermal melanocytosis, among others). The most common secondary disease of hyperpigmentation is post-inflammatory hyperpigmentation. This occurs when inflammation in the skin causes damage to the melanocytes containing pigment. This allows pigment to come out of the cells into the skin and clinically appear as areas of darker pigmentation compared with the normal skin color.
Similarly, the most commonly seen primary disorder of hypopigmentation is vitiligo. This is an autoimmune disease of the skin caused by destabilized melanocytes attacked by white blood cells, causing changes in the skin that appear as depigmented patches.
Secondary hypopigmentation disorders are usually due to a post-inflammatory reaction to inflammation as well.
Q: Who experiences dyschromia and dyspigmentation most often?
A. Dyspigmentation is most common in those who have skin of color, but these changes can occur in anyone. It is difficult to predict who will develop these disorders because it is not simply a matter of color of the skin, but also of genetic predisposition to the process.
Q: How do patients with psoriasis experience dyschromia and dyspigmentation?
A. Psoriasis is an inflammatory disease that causes damage to the melanocytes (the pigment-containing cells). White blood cells release inflammatory cytokines that damage the melanocytes and release pigment into the skin. Even after the inflammation and redness are cleared, post-inflammatory hyperpigmentation can persist because it takes months for the body to clear the pigmentation.
Q: How is skin of color affected by dyschromia and dyspigmentation differently from other populations?
A. Skin of color is not different compared with non-skin of color other than the fact that the melanocytes have larger aggregates of pigment in them. As a result, post-inflammatory hyperpigmentation is more common.
Q: What kind of stigma and affect on quality of life can dyschromia and dyspigmentation have?
A. Quality of life is known to be negatively affected by pigmentation abnormalities no matter if they are hypo- or hyperpigmentation issues. Others will often worry that the patient has an infectious process due to the pigmentation changes and avoid those who exhibit this issue.
In some cultures, vitiligo can be mistaken for leprosy, and those with vitiligo may be ostracized.
Q: What are some of the most popular treatment options?
A. For any dyspigmentation occurring as a result of an inflammatory process (acne, psoriasis, atopic dermatitis, etc), it is most important to treat the primary disorder first.
In some cases of hypopigmentation disorders, ultraviolet light therapy can be helpful. There are no other true treatments for hypopigmentation. There are experimental treatments that affect the melanocyte-stimulating hormones of the pituitary, but these are not available for general use.
In some cases of hyperpigmentation disorders, the mainstay of treatment is depigmenting agents such as hydroquinone. This is a drug that interrupts the cycle responsible for pigmentation. Other agents that be helpful include azelaic acid, topical vitamin C, topical kojic acid, topical retinoids, lasers, microdermabrasion and chemical peels. Recently, a new topical medication called cysteamine has been used for hyperpigmentation as well.
Sunscreen use is imperative in pigmentary disorders to prevent pigment darkening with treatment from the sun. Broad spectrum sunscreen is best, but the most protective sunscreen is inorganic or physical blocked containing either zinc oxides or titanium dioxide in a tinted sunscreen. The tint signifies that there is iron oxide in the sunscreen which is protective against visible light.
Q: What should clinicians think about before implementing a treatment plan, especially for patients with skin of color?
A. The main thing is to treat the underlying disease process. If it is not clear what the underlying disease is, that must be determined first. Discussing the pigmentary issue and the time it takes to improve the process with the patient is important. This allows them to understand the process.
For more information:
Amy J. McMichael, MD, FAAD, can be reached at Wake Forest School of Medicine, 475 Vine St., Winston-Salem, NC 27101; email: firstname.lastname@example.org.