Nevus of Ota: Clinical Aspects and Management

Henry H.L. Chan, MB, FRCPG, FRCPE, Taro Kono, MD

Disclosures
In This Article

Treatment of Nevus of Ota: Nonlaser Approaches

Although extracutaneous complications and melanoma can occur, they are uncommon, and most patients with nevus of Ota suffer from the psychological impact of cosmetic disfigurement. Before laser surgery, several treatments existed.

Camouflage is a time-honored means of covering facial defects. The use of camouflage materials disguises the appearance of patients who would have no other choice but to live with their deformities. Camouflage materials are opaque, waterproof, and formulated to adhere to nonabsorbent, slick scar tissue. Color correctors are worn underneath, with green color correctors counterbalancing redness, mauve or lavender color correctors counterbalancing yellowness, and orange color correctors counterbalancing blue pigmentation. Camouflage therapy is effective in correcting color changes, and the size of the defect is not important. The result depends upon the scar texture, because when it is camouflaged, skin irregularity tends to be exaggerated.

Before laser surgery, cryotherapy and dermabrasion were the main therapeutic options for the treatment of nevus of Ota. Cryotherapy lightened nevus of Ota by suppressing the function of epidermal melanocytes, as well as by destroying dermal melanocytes. There was direct cryonecrosis of the dermal melanocytes, and further damage by activated lysosomal enzymes. The dispersed melanosomes were either removed by histocytes through the lymphatic system, or, together with the cryodamaged tissue, were removed as an exfoliating crust. Liquid nitrogen (which generates temperatures in the range of 2180[ring]C) was considered to be more selective than other cryogens such as carbon dioxide snow (which generates temperatures in the range of 250[ring]C) because the extreme coldness of the former allows a shorter spray time and greater specificity. Dermabrasion removes epidermal and superficial dermal melanin, and in doing so may improve the clinical appearance. One study[30] used liquid nitrogen with spray durations that ranged from 5-10 seconds, and were successful in lightening nevus of Ota with or without dermabrasion. Another study[31] used combined dermabrasion and carbon dioxide snow cryotherapy to achieve "good" or "excellent" clinical outcomes in 22 out of 24 patients, with complications in only two. Nonetheless, our experience of patients who have previously been treated with cryotherapy for nevus of Ota suggests that there is a significant risk of scarring.

Microsurgery that creates a superficial scar has been used. Kobayashi[32] reported his experience of treating 32 patients with this technique; however, with advances in laser surgery, this method is no longer performed.

With the introduction of selective photothermolysis in 1983,[33] the use of the Q-switched (QS) laser has revolutionized the treatment of this condition (Figure 8 A & B). These systems provide high-energy radiation with short pulse durations, thus allowing the selective destruction of the target melanocytes. Goldberg and Nychay[34] and Geronemus[35] were among the first to report the use of QS ruby lasers to treat nevus of Ota. The clinical efficacy of the QS ruby laser (QS ruby) was later confirmed in a study of 114 nevus of Ota patients who had been treated with a QS ruby.[36] The study demonstrated that a good to excellent degree of lightening was achieved after three or more treatment sessions. The side effects were few, with transient hyperpigmentation after the first treatment being the most commonly encountered adverse effect. QS alexandrite and QS 1064 nm neodymium: yttrium-aluminum-garnet (QS 1064 Nd:YAG) were also used successfully for the removal of nevus of Ota.[37,38] Studies comparing the use of QS alexandrite and QS 1064 Nd:YAG lasers found that most patients showed a better tolerance for the former rather than the latter as a treatment modality.[39] However, the QS 1064 Nd:YAG laser was shown to be more effective than the QS alexandrite in the lightening of nevus of Ota after three or more laser treatment sessions.[40] In terms of complications, hypopigmentation was common, especially among those who were treated with the QS ruby.[41,42] The alternate use of QS alexandrite and QS 1064 Nd:YAG in different treatment sessions was also associated with a higher risk of complication.[41] The condition could also recur in patients with complete clearing after laser treatment.[43] The risk of such recurrence is estimated to be between 0.6%-1.2%. This is particularly important for children with nevus of Ota, as early treatment has been the standard practice. Early treatment, leading to complete clearance before school, can mean avoiding the childhood psychological trauma that is associated with the cosmetic disfigurement of the nevus. This advantage must now be weighed against the risk of recurrence and the stress that is associated with multiple sessions of laser surgery.

A patient before (top) and after (bottom) complete clearing of nevus of Ota after Q-switched 1064 Nd:YAG laser surgery

Nevus of Ota is a dermal melanocytic hamartoma that is commonly seen in Asians. Extracutaneous involvement is not uncommon, and should be monitored. The use of a QS laser can effectively clear the nevus, but recurrence is an issue, especially among children.

The print version of this article was originally certified for CME credit. For accreditation details, contact the publisher. Henry H.L. Chan, FRCPG, FRCPE, Division of Dermatology, Department of Medicine, The University of Hong Kong, Room 802, Administration Building, Queen Mary Hospital, Hong Kong. E-mail: hhlchan@hkucc.hku.hk

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