Nevi of Ota and Ito

Nevi of Ota and Ito - Blue-Gray Badges

• Definition: Dermal melanocytoses presenting as congenital or acquired blue-gray hyperpigmentation.
• Nevus of Ota:
  • Affects skin and mucous membranes innervated by trigeminal nerve branches.
  • Common sites: Periocular skin, sclera, conjunctiva, tympanic membrane.
  • 📌 Ota: Ocular/Ophthalmic involvement.

  ⭐ Involves areas of trigeminal nerve branches V1 (ophthalmic) & V2 (maxillary).

• Nevus of Ito:
  • Affects shoulder, neck, supraclavicular, and scapular regions.
  • Distribution: Posterior supraclavicular and lateral cutaneous brachial nerves.
• Features: Usually unilateral. Monitor for glaucoma and melanoma (rare).

and Nevus of Ito (shoulder/neck) showing characteristic blue-gray pigmentation) G

Nevi of Ota and Ito - The Who & Why

• Pathogenesis:
  • Arrested migration of melanocytes from neural crest to epidermis during embryogenesis. Melanocytes remain in dermis, causing dermal melanocytosis.
• Epidemiology:
  • Prevalence: Higher in Asian populations.
  • Gender: Predominantly affects females (F:M ratio ~5:1).
  • Age of Onset:
    • Congenital: ~50% present at birth or within first year.
    • Acquired: Can appear later, often around puberty or during pregnancy.

⭐ Associated with somatic mutations in GNAQ or GNA11 genes. Ocular melanocytosis (in Nevus of Ota) increases uveal melanoma risk.

Nevi of Ota and Ito - Spotting the Spots

• Congenital/early onset dermal melanocytoses; blue-gray, slate-gray, or brownish, mottled macules/patches.
• Nevus of Ota:
  • Distribution: Typically unilateral, periorbital (V1/V2 trigeminal dermatomes).
  • Involvement: Sclera (ocular melanocytosis), conjunctiva, tympanic membrane, nasal/oral mucosa.

  ⭐ Ocular melanocytosis (blue or gray scleral discoloration) is a hallmark; can be bilateral in ~10% of cases.

• Nevus of Ito:
  • Distribution: Unilateral; supraclavicular, deltoid, scapular regions.
• Differential Diagnosis (DDx):
  • Hori’s Nevus (ABNOM): Acquired, bilateral, malar/temple macules; no mucosal/scleral involvement.
  • Mongolian Spot: Congenital, lumbosacral, usually fades in childhood.
  • Melasma: Acquired, symmetrical facial hyperpigmentation.
  • Drug-induced pigmentation.

Nevi of Ota and Ito - Beyond the Blue

• Associated Conditions & Complications:
  • Glaucoma: Especially with ocular/palpebral involvement in Nevus of Ota. Annual screening vital.
  • Malignant Transformation (Rare, but serious; higher risk in Caucasians with Ota):
    • Uveal melanoma (most common ocular malignancy)
    • Cutaneous melanoma
    • CNS melanoma
  • Sensorineural hearing loss (rarely reported).
  • Phakomatosis pigmentovascularis (co-occurrence with vascular malformations like Sturge-Weber).

⭐ Patients with Nevus of Ota, particularly Caucasians, have an increased lifetime risk of developing uveal melanoma and glaucoma.

Nevi of Ota and Ito - Clearing the Canvas

• Diagnosis: Primarily clinical. Wood's lamp examination and dermoscopy assist.
  • Biopsy if atypical or malignancy concern: reveals dermal melanocytes without nevus cells.
• Management:
  • Observation for stable lesions.
  • Cosmetic camouflage for concealment.
  • Laser therapy: Q-switched Ruby, Alexandrite, Nd:YAG (e.g., 1064 nm) lasers. Multiple sessions are typically required.
• Follow-up: Regular ophthalmologic (glaucoma risk) and dermatologic (melanoma risk) surveillance is crucial.

⭐ Q-switched lasers (e.g., Nd:YAG, Ruby, Alexandrite) are the treatment of choice for cosmetic improvement, targeting dermal melanocytes.

High‑Yield Points - ⚡ Biggest Takeaways

• Nevus of Ota: Trigeminal (V1/V2) distribution; Nevus of Ito: Shoulder/neck (supraclavicular/deltoid).
• Both are dermal melanocytoses; bluish-grey patches, often congenital/early onset.
• Ocular melanocytosis (sclera) common in Ota, linked to ↑ glaucoma risk.
• Oral mucosal pigmentation possible in Nevus of Ota.
• Rare malignant transformation to melanoma (uveal, cutaneous), higher in Ota.
• Q-switched lasers for cosmetic improvement; regular eye exams for Ota patients monitoring for glaucoma and melanoma development.