What Causes Hyperpigmentation?

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Patient Presentation
A 15-year-old female came to clinic at the end of the summer for her health supervision visit and sports physical. She played volleyball and had been spending significant amounts of time outside playing sports over the summer. She had no concerns except that she had noted darker brown patches on sunexposed areas of her arms, thighs, face and upper chest. She had noticed them more over the course of the summer. They caused no pain or pruritis and she denied any swelling, erythema or scaling. She denied any drug use including not wearing sunscreen, as she stated, “Why should I wear it? I just tan and it gets in my eyes and sticks to the sand or grass when I play sports.” The past medical history and family history were non-contributory.

The pertinent physical exam showed a healthy female who was 90% for height and 25% for weight and was tracking appropriately. Her skin examination showed skin that was overall tanned, with what looked to be normal variations in skin tone, including her face. She had 1 cafe-au-lait lesion on her left shoulder/upper back that was 1.5 cm in size. She had no freckling of her face or axilla. She also had some mild closed comedomal acne on the bridge of her nose.

The diagnosis of a healthy female was made with tanning and one cafe-au-lait lesion, and mild acne. The pediatrician recommended for her to always use sunscreen especially as she lead an active lifestyle and was outdoors often. “Even if you tan, you still need to use sunscreen to prevent the risk of premature aging of your skin and skin cancer. Especially if you are outdoors a lot you need to have your skin checked at least every year and maybe more often as you get older. You can also use some benzoyl peroxide for your acne.” the pediatrician counseled. The teenager looked unimpressed with the diagnosis and counseling. “If you would like, I can refer you to the dermatologist who may have more specific recommendations for sunscreen and monitoring, and your acne,” she also offered. The teenager started to smile when the referral was offered.

Discussion
Skin color is primarily due to genetic factors. Melanocytes are usually found in skin in the basal layer of the epidermis which is also where the melanin usually lies. There are a range of normal skin phenotypes that have been described by Fitzpatrick and range from I-VI:

    I – pale white skin, blond hair, blue eyed, does not tan, always burns
    II – fair skin, blue eyed, tans poorly, burns easily
    III – darker white skin, burns initially then tans
    IV – light brown skin, tans easily, burns minimally
    V – brown skin, tans darkly easily, burns rarely
    VI – dark brown skin, always tans darkly, never burns

Melanocytes in increased numbers, producing more melanin or in abnormal locations can cause hyperpigmentation. Here are some examples:

  • Epidermal melanosis – increased melanin but normal number of melanocytes
    • Cafe-au-lait spots
    • Urticaria pigmentosa
  • Dermal melanosis – melanin in the dermis
    • Drug eruption
    • Incontinentia pigmenti
    • Lichen planus
    • Post inflammatory hyperpigmentation
  • Mixed – melanin in epidermis and dermis
    • Post inflammatory hyperpigmentation

Just like hypopigmentation (which can be reviewed here), hyperpigmentation can be worrisome for many families because of cosmesis and the worry that “something is wrong.” The normal natural changes in skin-tone over the year due to different light exposure and wide variations within individuals is not something that many people are aware of. Post-inflammatory hyperpigmentation is one of the most common causes of hyperpigmentation. Treatment can be difficult but mainstays are bleaching agents and laser therapy.

Learning Point
Some causes of hyperpigmentation include:

  • Normal variation
    • Tanning or increased UV light exposure
    • Familial periorbital hyperpigmentation
    • Futcher’s or Voight’s lines – sharp demarcation between normal and hyperpigmented skin
    • Joint extensor surfaces
    • Mongolian spots – dermal melanocytosis
    • Palmar or plantar hyperpigmentation – can also be due to medications or Addison’s disease
  • Abnormal
    • Post-inflammatory hyperpigmentation
    • Addison’s disease
    • Drugs
    • Dyschromatosis symmetric hereditaria
    • Familial progressive hyperpigmentation
    • Fanconi’s anemia
    • Lentiginosis – Peutz-Jeghers, LEOPARD syndrome
    • Lentigo solaris
    • Linear or whorled nevoid hypermalanosis
    • McCune-Albright syndrome
    • Melasma – due to pregnancy, contraceptives but also cosmetics, phototoxic drugs, anti-convulsants and UV-radiation
    • Metabolite accumulation – Gaucher’s disease, hemochromatosis
    • Neurofibromatosis type 1
    • Nevus of Ota or Nevus of Ito – grey-brown to blue color, often presenting around the time of birth. Nevus of Ota is on the face (Trigeminal nerve distribution – ophthalmic and maxillary branches), Nevus of Ito on shoulder and neck.
    • Renal failure
    • Vitamin B12 deficiency
    • Xeroderma pigmentosum

Questions for Further Discussion
1. How much SPF sunscreen factor is recommended? A review can be found here
2. What are the risks of ultraviolet light?

Related Cases

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: Skin Pigmentation Disorders

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.

Oakley A. Fitzpatrick skin phenotype. DermNet NZ. Available from the Internet at: https://www.dermnetnz.org/topics/skin-phototype/ (rev. 2012, cited 10/16/18).

Nieuweboer-Krobotova L. Hyperpigmentation: types, diagnostics and targeted treatment options. J Eur Acad Dermatol Venereol. 2013 Jan;27 Suppl 1:2-4.

Speeckaert R, Van Gele M, Speeckaert MM, Lambert J, van Geel N. The biology of hyperpigmentation syndromes. Pigment Cell Melanoma Res. 2014 Jul;27(4):512-24.

Nicolaidou E, Katsambas AD. Pigmentation disorders: hyperpigmentation and hypopigmentation. Clin Dermatol. 2014 Jan-Feb;32(1):66-72.

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

Published