Naevus of Ito

Naevus of Ito is a blue grey to brown patch of dermal melanocytosis over the shoulder, supraclavicular area, upper arm and scapular region, in the territory of the posterior supraclavicular and lateral brachial cutaneous nerves.

It is much less common than naevus of Ota but has the same background. It is seen mainly in Asian people, and often accompanies naevus of Ota in the same patient. It is present at birth or arises in early childhood or puberty.

The lesion is benign, and malignant change is very rare. It does not affect the eye.

Pathophysiology.

Persistent dermal melanocytes that did not migrate to the epidermis give a blue grey colour. Activating variants in GNAQ and GNA11 are found in related dermal melanocytic conditions.

• Unilateral, sometimes bilateral, speckled or confluent blue grey patch over the shoulder, side of the neck, supraclavicular area and upper arm.
• Slowly darkens at puberty. It is asymptomatic and does not resolve.

Red flags.

• A new nodule, ulceration or rapid growth within the patch.

• Clinical diagnosis from distribution and colour.
• Skin biopsy is needed only for a nodule or doubt: spindle and dendritic melanocytes in the dermis.
• Eye examination is advised when naevus of Ota is also present.

Differential diagnosis.

• Mongolian spot, blue naevus and naevus of Ota.
• Café-au-lait macule, Becker naevus and post-inflammatory hyperpigmentation.
• Ochronosis, drug induced pigmentation and macular amyloidosis.

• Reassurance that the lesion is harmless.
• Q-switched lasers (ruby, alexandrite or neodymium doped yttrium aluminium garnet) or picosecond lasers for cosmetic improvement, with 4 to 8 sessions at intervals of 3 months. Response is good, though slower than naevus of Ota because of the thicker skin, and the risk of post-inflammatory hyperpigmentation is higher in darker skin.
• Sun protection and camouflage cosmetics.
• Excision for any suspicious nodule, with histology.

Monitoring. Yearly skin check for new nodules.

Referral and escalation. Dermatology for laser; urgent review for a nodule or ulceration.