Swipe to advance
Image courtesy of DermNet NZ.

Lesions on Skin of Color: What You Need to Know

Carly A Elston, MD; Dirk M Elston, MD | January 20, 2022 | Contributor Information

The above image demonstrates dermatosis papulosa nigra, a benign cutaneous condition that affects up to 35% of individuals with skin of color.[1]

As the world's population demographics change, it is imperative that clinicians be familiar with variations in the prevalence, clinical presentation, and treatment of dermatologic disease in people with skin of color.[2,3] Several intrinsic differences in darkly pigmented skin contribute to these variations. For example, an increased melanin content not only raises the incidence of postinflammatory hyperpigmentation, but it can also make erythema in inflammatory skin disease difficult to recognize.[2,3]

Image courtesy of Dirk M Elston, MD.

Lesions on Skin of Color: What You Need to Know

Carly A Elston, MD; Dirk M Elston, MD | January 20, 2022 | Contributor Information

Keloids

The pathophysiology of keloid scar formation is not well understood, but upregulation of growth factor receptors on fibroblasts is thought to contribute to a higher propensity for keloid scars.[4] In contrast to hypertrophic scars, which are confined to the original wound margin, keloids exhibit clawlike extension beyond the site of injury into adjacent normal skin (shown) and are strongly associated with family history and particular human leukocyte antigen (HLA) types. They are seen more commonly in darker skin types, particularly in individuals of African descent.[4]

Images from Park HS, Cho KH. Cancers (Basel). 2010;2(2):642-52. [Open access.] PMID: 24281086; PMCID: PMC3835096. [Creative Commons Attribution 3.0 Unported license (CC by 3.0).]

Lesions on Skin of Color: What You Need to Know

Carly A Elston, MD; Dirk M Elston, MD | January 20, 2022 | Contributor Information

Acral Lentiginous Melanomas

Individuals with pigmented skin generally do not develop sun-related melanomas—although the incidence is rising among this population.[3] However, acral lentiginous melanomas occurring on non–sun-exposed sites (eg, nails, palms, soles) (shown) make up a disproportionate number of melanomas in Asian, Hispanic, and Black individuals.[2] Because of the difficulty in distinguishing early acral lentiginous melanoma from benign lesions as well as the morbidity potential of acral biopsies, it is disproportionately diagnosed when in a more advanced stage.

Image courtesy of Dirk M Elston, MD.

Lesions on Skin of Color: What You Need to Know

Carly A Elston, MD; Dirk M Elston, MD | January 20, 2022 | Contributor Information

Melanonychia

Melanonychia, in which there is linear brown/black pigmentation of the nail plate, occurs more commonly in skin of color, being found particularly in Afro-Caribbean and Japanese individuals.[5,6] This condition can result from melanocyte hyperplasia or activation of melanocytes by pregnancy, trauma, inflammatory skin disease, endocrinopathy, and certain medications. Commonly implicated medications include hydroxyurea, bleomycin, cyclophosphamide, 5-fluorouracil, and antimalarial agents.[6,7]

Benign melanocytic proliferations can occur within the nail matrix, with lentigines ("liver spots") occurring more commonly in adults and nevi occurring more commonly in children.[6,7] These lesions typically do not require treatment.

Worrisome features that raise suspicion for nail matrix melanoma include extension of the pigment onto the hyponychium or proximal nail fold (Hutchinson sign), irregular pigmentation, width greater than 3 mm, and widening of the pigment at the proximal aspect.[5-7]

Image courtesy of Dirk M Elston, MD.

Lesions on Skin of Color: What You Need to Know

Carly A Elston, MD; Dirk M Elston, MD | January 20, 2022 | Contributor Information

Dermal Melanocytosis (Mongolian Spot)

The blue-to-gray patches on the buttocks and sacral skin of the patient shown above are consistent with a Mongolian spot. The blue color of the deep dermal pigment results from the scattering of light known as the Tyndall effect.[8]

Dermal melanocytosis is most common in Asian, Hispanic, Black, and Native American populations.[8,9] It is usually present at birth and tends to regress during childhood, although lesions, especially those that are extrasacral, may persist into adulthood in some individuals.[8] In general, no treatment is needed.

Infants with extensive dermal melanocytosis should be evaluated for the presence of a vascular lesion that would suggest a diagnosis of phakomatosis pigmentovascularis (capillary malformation and melanocytic lesions), as well as for potential inborn errors of metabolism.[8] Extensive lesions involving the back should prompt radiologic evaluation to rule out a spinal meningeal tumor/anomaly.

Image courtesy of Dirk M Elston, MD.

Lesions on Skin of Color: What You Need to Know

Carly A Elston, MD; Dirk M Elston, MD | January 20, 2022 | Contributor Information

Hypopigmentation

Spongiotic processes

Spongiotic processes such as atopic dermatitis that would be pink or erythematous on white skin are often hypopigmented in individuals with darkly pigmented skin, as shown in the above image of pityriasis alba.

Pityriasis alba

Pityriasis alba is caused by a low-grade eczematous dermatitis[10] that disrupts the transfer of melanosomes from melanocytes to keratinocytes, resulting in characteristic ill-defined, hypopigmented patches with fine scale. Perifollicular accentuation and papular eczema are also common features of eczema in skin of color.[11]

Atopic dermatitis

Atopic dermatitis (eczema), a chronic, pruritic inflammatory skin disease,[12] has a higher prevalence and severity in Black and mixed-race populations, likely due to a combination of environmental and intrinsic factors.[13] Black skin has been shown to have increased transepidermal water loss and lower levels of ceramides, which are important components of the lipid barrier in the stratum corneum.[13]

Image courtesy of Dirk M Elston, MD.

Lesions on Skin of Color: What You Need to Know

Carly A Elston, MD; Dirk M Elston, MD | January 20, 2022 | Contributor Information

Inflammatory processes

Pigmentary disruption is a common complication of inflammatory disease in darkly pigmented skin, and it can have a significant psychological impact on patients.

Postinflammatory hypomelanosis is a common cause of acquired hypopigmentary conditions, particularly when severe cutaneous inflammation is present.[14,15] This condition can be seen with chronic scratching, as shown above in a patient with chronic dermatitis,[14] and it usually coexists with inflammatory lesions. In some patients, however, hypopigmentation may be the only manifestation of the disease.[15]

Image courtesy of Dirk M Elston, MD.

Lesions on Skin of Color: What You Need to Know

Carly A Elston, MD; Dirk M Elston, MD | January 20, 2022 | Contributor Information

Hyperpigmentation

Postinflammatory hyperpigmentation results from destruction of the basal layer of the epidermis, as occurs in lichenoid dermatoses such as lichen planus (shown), fixed drug eruptions, and systemic lupus erythematosus.[16,17] Melanin pigment that is normally contained within the basal layer is released into, and trapped in, the dermis, resulting in hyperpigmentation of the skin.[16,17]

Although postinflammatory hyperpigmentation eventually fades with time, the process can take months or years in darkly pigmented individuals, which can be psychologically distressing.[16,17] Sun exposure can accentuate the hyperpigmentation; therefore, patients should be counseled on rigorous sun protection.

Image courtesy of Dirk M Elston, MD.

Lesions on Skin of Color: What You Need to Know

Carly A Elston, MD; Dirk M Elston, MD | January 20, 2022 | Contributor Information

Scarring Alopecia

This image demonstrates progressive scarring alopecia in a patient with acne keloidalis nuchae and folliculitis decalvans.[18] Note the firm keloidal papules on the occipital scalp and the scarred atrophic alopecic plaques.

1 26 Next
References