Last updated: May 2024
What are naevus of Ota (NOO) and Ito (NOI)?
Naevus of Ota (NOO) and Ito (NOI) are pigmented birthmarks that are slate-brown or blue/grey in colour. When examined under a microscope, the pigmented naevus cells are found in the deep layer of the skin (dermis).
Who get naevus of Ota (NOO) and Ito (NOI)?
NOO and NOI are mostly found within Asian populations and are uncommon in Caucasians. Women are more frequently affected than men.
What cause naevus of Ota (NOO) and Ito (NOI)?
The precise cause is unknown. However, GNAQ or GNA11 mutations have been found in the dermal melanocytes seen in this condition. Hormones may play a role.
What do naevus of Ota (NOO) and Ito (NOI) look like?
NOO and NOI are smooth, non-scaly blue-grey, blue-brown spots. They are usually small spots that connect to form larger continuous areas of pigmentation.
NOO refers to a lesion, usually present at birth or young adulthood, on one side of the forehead and around the eye. Some individuals may also have pigment on the sclera (eyeball), cornea and inside the mouth including the palate.
NOI occurs on the shoulder and upper arm region and is present at birth in the majority of instances. It may coexist with NOO.
How are naevus of Ota (NOO) and Ito (NOI) diagnosed?
NOO and NOI are usually diagnosed after examining the colour and pattern of the pigment. A small sample of skin (biopsy) may be taken to confirm the diagnosis and exclude other causes of pigmentation such as melasma, medication-induced pigmentation, lichen planus pigmentosus and post-inflammatory pigmentation.
How are naevus of Ota (NOO) and Ito (NOI) treated?
Treatment options will vary depending on the individual and their needs.
Camouflage with makeup is often considered as a treatment for NOO and NOI, but achieving cosmetically acceptable skin colour matching can be difficult.
Laser is often the main treatment used for both these conditions. Quality(Q)-switched lasers (Nd:YAG (1064nm and/or 532nm), Ruby (694nm) or Alexandrite (755nm)) are usually used to lighten pigmentation, but several treatment courses are required. Newer picosecond lasers (755nm and 1064nm) may also be used.
If the eye is affected with pigmentation, a referral to an ophthalmologist may be necessary.
What are the likely outcomes of naevus of Ota (NOO) and Ito (NOI)?
Good clinical outcomes can be achieved with near complete resolution of NOO and NOI in some cases where laser therapy has been used. However, multiple treatment sessions are often required over several years to improve the cosmetic appearance.
| Dr Michelle Rodrigues | May 2024 |
| Dr Michelle Rodrigues | November 2015 |