What is in the Differential Diagnosis for Black and White Skin Conditions?

Patient Presentation
A 2 year-old African-American female came to clinic with white spots her mother was concerned because they were worsening. The spots were mainly on her face and arms but also a few on her trunk and had been worsening in that they were more prominant for about 1 month. The mother denied any new soaps, lotions/detergents or other products. She was using sunscreen intermittently. She had been to the pool more often because it was summer. She was otherwise well. The past medical story was positive for atopic dermatitis.

The pertinent physical exam showed a healthy appearing toddler with normal vital sign and growth parameters in the 50%. She had mild, generalized xerosis but also areas where she had more patches of reddened skin. She also had similar areas of 1-3 cm in size that were lighter to quite white in color with a blended border that was not punched out or discrete. The red and white patches were mainly on the face, upper trunk and extremities.

The diagnosis of atopic dermaitis with post-inflammatory skin changes was made. The physician explained that most likely the combination of atopic dermatitis, pool and possibly sunscreen chemical exposure probably was irritating her skin, and after the inflammation there can also be either lightening or darkening of the skin.
The sun exposure could also make her skin darken through tanning, all of which makes the white areas more prominent. She recommended continuing to use the sunscreen as the toddler had not had reactions to it in the past. She also recommended that the child shower after pool exposure and put on liberal amounts of additional sunscreen or emollients. Topical steroids were not recommended as she thought that emollients would help with the reddened areas. “If we can stay away from steroids I always try to do that. Plus steroids can also cause lightening of the skin as well for some people,” she explained. She also reviewed pool and summer safety with the mother.

This is the third in a short case series of differential diagnoses of colored skin conditions.
An introduction to dermatological terminologies and information about colors can be can be found here.
A differential diagnosis by distribution and common pattern can be found here.
For red, orange and yellow conditions, a review can be found here.
For green, blue and purple conditions, a review can be found here.
For brown and grey conditions, a review can be found here.

Note that any color can be a normal variant for an individual or is physiologic for a given state. When lesions of the opposite color of the normal skin tone occur, this can be worrisome for individuals.

From a physics standpoint, black and white are not colors. Black and white do not have specific visual spectral wavelengths. Instead, black absorbs all the waves in the visible spectrum (none are reflected back to see the color), and white reflects back all the wavelengths. From an artistic or daily living viewpoint, black and white are described/treated as colors.

Learning Point
Black is not in the visible spectrum of light.
The differential diagnosis for black skin conditions includes:

  • Skin
    • Acne – blackhead or open comedome
    • Acanthosis nigricans
    • Blue nevus
    • Calciphylaxis
    • Dermatosis papulose nigra
    • Discoid lupus erythematosus
    • Ecthyma gangrenosum
    • Exogenous ochronosis
    • Foreign body
    • Hematoma
    • Ink spot lentigo
    • Infection
      • Mucormycosis
      • Tinea nigra
      • Verrucae plantaris
    • Neoplasms
      • Basil cell carcinoma
      • Melanoma
      • Reed nevus or pigmented spindle nevus
      • Seborrheic keratosis, pigmented
    • Staining
      • Black dermatographism
      • Tattoo – intentional or traumatic
    • Vasculitis and embolism
      • Black heel or calcaneal petechiae
      • Frostbite
      • Gangrene
      • Thromboembolic disease
  • Hair
    • Black dot tinea capitus
    • Black piedra
  • Nail
    • Subungual hematoma
    • Melanonychia
  • Mucosa
    • Amalgam reactions
    • Black harry tongue

White is not in the visible spectrum of light
The differential diagnosis for white skin conditions includes:

  • Skin
    • Actinic keratosis
    • Albinism
    • Blanching, normal
    • Degos disease
    • Chemical exposure including lead
    • Halo nevus of Sutton
    • Happle syndrome
    • Hand-arm vibration syndrome
    • Idiopathic guttate hypomelanosis
    • Intralesional steroid injection
    • Lichen sclerosus et atrophicus
    • Lichen striatus
    • Melasma
    • Milia
    • Localized hypopigmentation including ash-leaf spots
    • Piebaldism
    • Pityriasis alba
    • Pityriasis licenoides chronica
    • Psoriasis
    • Post-inflammatory reaction
      • Atopic dermatitis
      • Candidal dermatitis
    • Sun bleaching
    • Tinea versicolor
    • Urticaria
    • Vitiligo
    • Waardenburg syndrome
  • Hair
    • Chemical exposure
    • Depigmentation
    • Sun bleaching
    • UV light leukoderma
  • Nail
    • Leukonychia
    • Trauma
  • Mucosa – often temporary
    • Trauma
    • Infection

Questions for Further Discussion
1. What black skin conditions do you see often?
2. What white skin conditions do you see often?
3. What are indications for referral to a dermatologist?

Related Cases

    Symptom/Presentation: Rash

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for this topic: Rashes

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Brown AE, Qiu CC, Drozd B, Sklover LR, Vickers CM, Hsu S. The color of skin: white diseases of the skin, nails, and mucosa. Clinics in Dermatology. 2019;37(5):561-579. doi:10.1016/j.clindermatol.2019.07.018

Qiu CC, Brown AE, Lobitz GR, Shanker A, Hsu S. The color of skin: black diseases of the skin, nails, and mucosa. Clinics in Dermatology. 2019;37(5):447-467. doi:10.1016/j.clindermatol.2019.08.003

Visible spectrum. In: Wikipedia. 2021. Accessed January 4, 2022. https://en.wikipedia.org/w/index.php?title=Visible_spectrum&oldid=1062416030

Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa