The color of skin: gray diseases of the skin, nails, and mucosa

Clin Dermatol. 2019 Sep-Oct;37(5):507-515. doi: 10.1016/j.clindermatol.2019.07.011. Epub 2019 Jul 31.


Gray diseases are a group of skin disorders characterized mainly by gray discoloration with or without involving the mucous membranes and nails. These diseases may be hereditary or acquired. Some of the better-known hereditary entities are dermal melanocytosis, incontinentia pigmenti, hypomelanosis of Ito, hemochromatosis, ochronosis, and silvery hair syndrome. Acquired diseases with gray coloring include late-stage organ failure, lichen planus pigmentosus, erythema dyschromicum perstans, and drug reactions. The discoloration is due to either increased epidermal and or dermal melanin or dermal deposition of a chromogen or a combination of both. Investigations are directed to determining the underlying medical condition and a skin biopsy is usually unnecessary. Likewise, treatment is directed mainly toward the underlying medical disease. Although bleaching (lightening) agents may diminish the discoloration, better results may be obtained from using a Q-switched laser and intense pulsed light, either alone or in combination with topical agents.

MeSH terms

  • Anti-Bacterial Agents / adverse effects
  • Color
  • Drug Eruptions / etiology
  • Hemochromatosis / complications
  • Humans
  • Hyperpigmentation / diagnosis
  • Hyperpigmentation / etiology*
  • Hyperpigmentation / genetics
  • Incontinentia Pigmenti / diagnosis
  • Metals, Heavy / adverse effects
  • Mongolian Spot / complications
  • Mucous Membrane
  • Nail Diseases / etiology
  • Nevus of Ota / complications
  • Ochronosis / complications
  • Skin Neoplasms / complications*


  • Anti-Bacterial Agents
  • Metals, Heavy

Supplementary concepts

  • Ochronosis, hereditary