What are Ota, Ito and Hori naevi?

  • Naevus of Ota is on the forehead and face around the eye area. Hyperpigmentation of parts of the eye may occur (sclera, cornea, iris, retina)
  • Naevus of Hori is similar to naevus of Ota but affects both sides of the face
  • Naevus of Ito is on the shoulder and upper arm area (shoulder girdle).
Dermal melanocytosis can also occur elsewhere on the body, including inside the mouth.

What are the signs, symptoms and complications of dermal melanocytosis?

In all forms of dermal melanocytosis:
  • Colour may vary to include brown-violet, violet-blue or blue-green hues
  • Naevi present in childhood may slowly grow and darken until adulthood is reached
  • Colour or perceived colour of naevi may change according to personal and environmental conditions, e.g. fatigue, menstruation, hot weather
  • If affecting the eye, melanocytosis rarely causes glaucoma
  • Melanoma very rarely develops within dermal melanocytosis, and has usually been reported in Caucasians. Ocular melanoma has rarely been reported in the choroid, brain, orbit, iris, ciliary body, and optic nerve in association with a nevus of Ota.