Nevus of Ota refers to a pigmented lesion ranging in color from brown to bluish, typically occurring on the face in areas innervated by the first and second branches of the trigeminal nerve.
It is most commonly observed in Asians, including Japanese individuals. The condition was reported in 1939 by Masao Ota as naevus fuscocaeruleus ophthalmomaxillaris, hence the name “Nevus of Ota.” However, earlier descriptions exist: Hulke reported similar pigmentation involving the eyeball and facial skin in 1861, and in 1916, Pusey described a comparable case in a Chinese student. Although rare, cases have also been reported in Black and Caucasian individuals (Watanabe).
Today, the term “Nevus of Ota” is widely accepted internationally. Some authors argue that it is not a true nevus but rather a form of dermal melanocytosis characterized by an increased number of dermal melanocytes (Watanabe). However, the definition of a “nevus” itself remains ambiguous.
Various definitions have been proposed:
“A malformation of the skin or mucosa exhibiting abnormalities in color or shape” (Unna)
“A lesion of the skin or mucosa caused by genetic mosaicism, typically lacking proliferative tendency” (Happle)
“What has historically been called a nevus is, by definition, a nevus” (Jadassohn)
Because earlier clinicians applied the term “nevus” to a wide variety of conditions, it is difficult to establish a precise and universal definition (Mitsuhashi).
Clinical Features
The coloration varies—black-brown, blue, or gray—but typically consists of a grayish-blue base with superimposed brown tones. This variation reflects the depth of melanin deposition:
Black: melanin in the stratum corneum
Dark brown: melanin in the epidermis
Light brown: melanin in the basal layer
Gray: melanin in the papillary dermis
Blue: melanin in the deeper dermis
Approximately 70% of lesions are diffuse, while 30% present as speckled, freckle-like spots.
In some cases, bluish pigmentation may appear in the conjunctiva or sclera (ocular melanosis). Palatal melanosis may also be observed (Watanabe).
Nevus of Ota is classified into four types based on extent and severity:
Type I (Mild)
a. Orbital type: pigmentation around the eyelids resembling a “panda” pattern
b. Zygomatic type: crescent-shaped pigmentation on the lower eyelid
c. Frontal type: crescent-shaped pigmentation above the eyebrow
d. Alar type: pigmentation on the nasal ala
Type II (Moderate)
Pigmentation resembling an eye-mask over one side of the face
Type III (Severe)
Extensive unilateral involvement from the forehead to the eyelids, cheek, and sometimes the temporal region
Type IV (Bilateral)
a. Symmetrical type: includes acquired dermal melanocytosis (ADM) / symmetrical dermal melanocytosis (SDM)
b. Asymmetrical type
Age of Onset
Most cases appear within several months after birth, although onset in adolescence or adulthood is also reported. The pigmentation tends to darken and expand until puberty.
Histopathology
Melanocytes are found scattered within the dermis at various depths, from superficial to deep layers. They are distributed along collagen bundles without disrupting dermal architecture.
During embryogenesis, melanocytes migrate from the neural crest to the epidermal basal layer. If this migration is incomplete, melanocytes remain in the dermis, resulting in dermal melanocytosis.
Treatment
Q-switched laser therapy is the gold standard. (Details are discussed in the section on dermal melanocytosis.)
Compared with ADM/SDM, Nevus of Ota involves a greater amount of pigment and deeper dermal distribution, requiring more treatment sessions. Adequate intervals (at least 3–4 months) between sessions are necessary; otherwise, treatment efficacy may decrease, and complications such as hypopigmentation may occur.
Treatment outcomes vary by location: the temple area (overlying bone) responds best, whereas the eyelids are the most resistant.
Because of significant pain—especially in the eyelids—topical anesthesia alone is often insufficient, and local anesthetic injections may be required. In children, general anesthesia may be necessary. Protective contact lenses are used to shield the eyes from laser exposure (Watanabe).
Although Nevus of Ota occurs on the face, similar lesions can appear on the shoulder region, known as Nevus of Ito, which is about one-twentieth as common.
Differential Diagnosis
Symmetrical Dermal Melanocytosis (SDM):
-Later onset
-More superficial dermal pigmentation → more brownish tone
-Less color variation (no bluish hues)
-Darkens with age
Approximately ten times more common than Nevus of Ota, predominantly in women
However, the distinction between bilateral Nevus of Ota and SDM is not always clear-cut.
Mongolian Spot
Type I (mild) cases may resemble ectopic Mongolian spots
Typically uniform blue to gray-blue color
Gradually fades over time
However, ectopic Mongolian spots may persist into adulthood, and color differences are not always distinct, making differentiation difficult.
Even after reviewing textbooks, I find that distinguishing atypical or peripheral cases of Nevus of Ota remains challenging.
Final Remarks
Dermal melanocytosis is a complex and fascinating field. Just as there is diversity among races and individuals, there is also considerable variability in pigmentary disorders, making precise classification inherently difficult.
Although I intended to provide a concise summary, the result may feel somewhat unfocused. I ask for your understanding.
References
Furue M, Ichihashi M, eds. Clinical Asset in Dermatology 11: Pigmentation and Vitiligo—A Practical Guide. Tokyo: Nakayama Shoten; 2011.
(Chapter 16: Mizoguchi M, Murakami F. Pathophysiology and diagnosis of nevus of Ota.)
Furue M, Kaneda M, eds. Clinical Asset in Dermatology 15: Nevi and Nevus Syndromes—An Update. Tokyo: Nakayama Shoten; 2011.
(Chapter 18: Murakami F. Nevus of Ota.
Chapter 19: Murakami F. Nevus of Ito.)
Watanabe S, Iwasaki Y, Kasai K. Professional Dermatologic Laser Therapy: Principles and Practice. Tokyo: Nankodo; 2013.
(Section B: Pigmentary disorders. Watanabe S.)
Suzuki H, Kanzaki T, eds. Color Atlas of Dermatology, Vol. 3: Pigmentary Disorders and Others. Tokyo: [publisher not specified].
(Watanabe S. Nevus of Ota; Laser treatment of nevus of Ota.)
Watanabe S, Takahashi H. Treatment of nevus of Ota with the Q-switched ruby laser. N Engl J Med. 1994;331:1745–1750.
This overview is based on standard dermatology references and clinical observations.
Figure 1.
Clinical appearance of nevus of Ota on the face.
Bluish to grayish pigmentation is distributed along the area innervated by the ophthalmic and maxillary branches of the trigeminal nerve.
Figure 2.
Facial pigmentation showing a mixed pattern of brown and blue coloration.
Variation in color reflects differences in the depth of melanin deposition within the skin.
Figure 3.
Ocular melanosis associated with nevus of Ota.
Bluish pigmentation is observed in the sclera.
Japanese version: