Acquired, bilateral nevus of Ota-like macules. L81.1

Hori Y et al. 1984

Acquired, bilateral nevus of Ota-like macules (ABNOM), first described in 1984 as "Hori nevus", is a common acquired dermal melanocytosis in Asian women. ABNOM was previously regarded as a variant of the nevus of Ota.

In a Chinese collective (n=3212 patients), the outpatient prevalence of ABNOM was 3.18%.

The etiopathogenetic factors have not yet been clarified (Zhang Q et al. 2017). Excessive sun exposure, hormonal disorders and hereditary susceptibility are cited as the main potential causes of ABNOM. In a Chinese collective, individual analysis of the triggering factors revealed indications of UV radiation (47.1 %), pregnancy (32.0 %), cosmetics (29.4 %), sensitive skin (22.6 %) and a positive family history (21.6 %) (Wang B et al. 2016).

The average age at onset was 27.2 years.

ABNOM usually occurs as bilaterally symmetrical but asymmetrical, partly speckled, partly flat brownish-yellowish, also rich brown spots on the face (zygomatic arch, periorbital region, cheek area, parotid gland region) (17.7 %), sometimes combined with band-like or extensive pigmentation. Pigmentation of the sclera has been reported.

In a larger Chinese collective, ABNOM occurred frequently (20-40%) together with pigmented mushroom-shaped papillae of the tongue, with melasma, with premenstrual syndrome and cystic breast hyperplasia (in women). It was shown that patients with ABNOM had an increased risk of concomitant melasma with increasing age. The pigmentation of the lesion also increases with age.

In ABNOM, slender, pigment-containing cells are found scattered in the middle and upper parts of the dermis, with some melanocytes distributed in the perivascular area (Yang X et al. 2023).

Laser treatment has established itself as a common treatment method for ABNOM. Successes have been achieved with the 1064-nm Q-switched neodymium:yttrium aluminum garnet (Nd:YAG) laser (Wang B et al. 2016).

1. Hori Y et al. (1984) Acquired, bilateral nevus of Ota-like macules. J Am Acad Dermatol. 10:961-964
2. Lee JY et al. (2010) Histopathological features of acquired dermal melanocytosis. Eur J Dermatol. 20:345-348.
3. Wang B et al. (2016) Induction of melasma by 1064-nm Q-switched neodymium:yttrium-aluminum-garnet laser therapy for acquired bilateral nevus of Ota-like macules (Hori nevus): A study on related factors in the Chinese population. J Dermatol 43:655-661.
4. Yang X et al. (2023) A retrospective study of 1064-nm Q-switched Nd:YAG laser therapy for acquired bilateral nevus of Ota-like macules. Skin Res Technol 29:e13298.
5. Zhang Q et al. (2017) Clinical profile and triggering factors for acquired, bilateral nevus of Ota-like macules. Cutan Ocul Toxicol 36:327-330.