Some skin problems occur more frequently in people with dark or black skin than in those with white skin.
Due to natural sun protection (melanin), the prevalence of skin cancer is lower in people with dark skin, and both the localization and the clinical picture differ from those in people with white skin.
Samples for fungal testing should be taken from any scaly rash (particularly on the scalp of children with dark skin).
Innocent findings
Demarcation lines on the limbs between lighter and darker skin (Futcher lines or Voigt lines).
A dark line along the midline of the abdomen (linea nigra), which may also be light (hypopigmented) and is then usually above the navel.
Hyperpigmented keratotic palmar pitting and lines.
Dark longitudinal lines usually underneath several nails (melanonychia).
Dark spots on the mucosa (lips, tongue, gums, insides of cheeks).
Dark bluish pigment spots on the lower back and buttocks in babies (mongolian spots; Image 1)
Dark bluish pigment spots on the face (naevus of Ota) or shoulders and upper back (naevus of Ito) are usually congenital but may not appear until teen age.
Darkening of the skin (hyperpigmentation) after an eczema, inflammation or ulcer has healed; this is usually transient. See also Skin colour changes and pigmentary disorders Skin Colour Changes and Pigmentary Disorders.
Curved hair follicles and naturally curly hair explain some of the typical skin problems (pseudofolliculitis). Hair styling and hair styles (treatments, straightening) may cause scalp problems (irritant or seborrhoeic eczema) or hair problems (brittle hair, traction alopecia) Scalp Problems.
Special features of dark skin in association with some common skin problems
Acne Acne: hyperpigmentation, acne scars and keloids are more common; topical treatment may promote irritation and darkening.
Eczemas, such as atopic eczema Atopic Eczema (Atopic Dermatitis) in Adults: a papular and lichenified clinical picture is more common; the skin may remain darker after healing.
Hyperpigmentation may hide erythema and thus complicate assessing the severity of the disease; it may be falsely interpreted as less severe.
Ringworm Dermatomycoses: more common in children with dark skin; scaling on the scalp, circular scaling on the limbs.
Postinflammatory hyperpigmentation Skin Colour Changes and Pigmentary Disorders: darkening of the skin after eczema or ulcer; usually subsides with treatment of the cause and slowly with time.
Skin problems with a higher prevalence in people with dark skin
Dermatosis papulosa nigra: benign dark papules on the face and neck; genetic predisposition, no need for treatment
Pseudofolliculitis barbae: papules and folliculitis on the face and neck, particularly on bearded area; due to ingrowing hair
Acne keloidalis nuchae: chronic folliculitis on the back of the head and neck; papules and suppurative areas, often in a band-like distribution at the nuchal fold, with scarring hair loss; more common in men
Disorders lightening the skin are more visible in people with dark skin types and may therefore cause significant cosmetic distress.
Vitiligo Vitiligo: hypopigmented, asymptomatic, clearly defined patches, usually symmetrically on the limbs, in the navel area and on the nipples, around the mouth and eyes
Pityriasis versicolor Pityriasis Rosea: on dark skin, usually causes light spots with slight scaling
Pityriasis alba: slightly scaly white patches predominantly on the face and upper limbs; cause unknown, possibly postinflammatory hypopigmentation in atopic eczema
Progressive patchy hypomelanosis: usually in people with dark skin; asymptomatic white patches on the trunk, neck and proximal limbs, often merging in the midline; cause uncertain
Skin cancers
The clinical picture and localization often differ from those in white people.
Basalioma Basal Cell Carcinoma: usually a slow-growing, pigmented papule that may be ulcerated; in areas of skin exposed to light, particularly on the face or neck
Squamous cell carcinoma Basal Cell Carcinoma: a growing, pigmented plaque or nodule covered by hyperkeratosis; on black skin usually in areas unexposed to light; may occur in areas with chronic scarring or ulceration, such as an old burn; on lower limbs, genitals, scalp
Actinic keratosis: rarer, usually dark patches, scaling may be absent
Melanoma Melanoma: usually in areas unexposed to light; the acral type is the most common, occurring on feet and hands, nail folds, and underneath nails
Workup
The required workup is presented in the specific articles for each skin disorder.
Samples for fungal testing should be taken from any areas with scaly eczema (in children, particularly, the scalp).
In unclear cases, perform a biopsy and microscopic examinations.
Treatment
The treatment is presented in the specific articles for each skin disorder.
In a person with dark skin, combination gels may be more effective against acne than topical monotherapy Acne.
Topical treatment should best be started with mild products (causing less irritation and hyperpigmentation); for example, first every 2 to 3 days for 2 to 3 weeks and then daily.
Topical azelaic acid ointments and gels are effective and well tolerated and may also help with hyperpigmentation associated with acne.
For postinflammatory pigmentary disorders, treatment of the causative skin disease helps.
The response in the pigmentary disorder itself is often poor but the skin tone will often even out in 6-12 months; use of a sunscreen ointment may speed up lightening.
Dermatosis papulosa nigra lesions can be surgically removed for cosmetic reasons. Patients must be informed that scars may remain. Lesions can be removed by scissor excisions, curettage, electrocautery, cryotherapy or laser, for example.
Pseudofolliculitis barbae usually heals completely only when the patient stops depilating or changes the method used.
Patients with acne keloidalis nuchae should be instructed to wear loose collars and to stop cutting the hair at the back of the head.
For both disorders, symptomatic treatment with low- or mid-potency topical glucocorticoids and antimicrobial solutions (clindamycin, for instance) intermittently in courses of 2 to 3 weeks has been used. Topical retinoids and benzoyl peroxide gel are suitable for maintenance treatment.
For exacerbations, 1 to 2 weeks of oral antimicrobial treatment effective against S. aureus, such as 500 mg cephalexin three times daily, may be needed in addition to topical treatment Skin Abscess and Folliculitis.
In unclear cases or skin problems resistant to treatment, consult a dermatologist.
References
Dunwell P, Rose A. Study of the skin disease spectrum occurring in an Afro-Caribbean population. Int J Dermatol 2003;42(4):287-9. [PubMed]
Kundu RV, Patterson S. Dermatologic conditions in skin of color: part II. Disorders occurring predominately in skin of color. Am Fam Physician 2013;87(12):859-65. [PubMed].
Agbai ON, Buster K, Sanchez M et al. Skin cancer and photoprotection in people of color: a review and recommendations for physicians and the public. J Am Acad Dermatol 2014;70(4):748-762. [PubMed]
Coley MK, Alexis AF. Managing common dermatoses in skin of color. Semin Cutan Med Surg 2009;28(2):63-70. [PubMed]
Shah SK, Alexis AF. Acne in skin of color: practical approaches to treatment. J Dermatolog Treat 2010;21(3):206-11. [PubMed]
Higgins S, Nazemi A, Chow M et al. Review of Nonmelanoma Skin Cancer in African Americans, Hispanics, and Asians. Dermatol Surg 2018;44(7):903-910. [PubMed]