Characteristics of Hori naevus: a prospective analysis

Exploring the potential of intradermal platelet-rich plasma in treating acquired bilateral nevus of Ota-like macule (Hori's nevus): A pilot study

BACKGROUND

Hori's nevus is a common and challenging dermatological condition, often complicated by post-inflammatory hyperpigmentation following treatment. Platelet-rich plasma (PRP) has demonstrated efficacy in the treatment of hyperpigmentation disorders such as melasma and periorbital darkening. Given the benefits and minimally invasive nature of PRP treatments, exploring its application in managing Hori's nevus through further investigation is worthwhile.

AIMS

To evaluate the safety and effectiveness of intradermal PRP therapy for the treatment of Hori's nevus.

METHODS

Ten female patients received bilateral intradermal PRP injections every 2 weeks for a total of four treatments. The modified dermal pigmentation and severity index (mDPASI), mean melanin index (MI), brightening score, patient self-assessment, and clinical photographs were evaluated at 2, 4, 8, and 12 weeks post-treatment. Adverse events were also recorded to determine treatment safety.

RESULTS

At 12 weeks post-treatment, mDPASI decreased 38.86%, from 0.929 ± 0.617 to 0.568 ± 0.415 (p < 0.05). The mean melanin index decreased 12.75%, from 208.650 ± 26.319 to 182.052 ± 17.028 (p < 0.05). In addition, the mean brightness score evaluated by two experts was 1.4, indicating 25-50% improvement. At the end of the study, 50% of the patients reported 50-75% improvement. Side effects included pain, mild edema, and bruising, which resolved spontaneously within 3 days. No serious side effects were found.

CONCLUSION

Our results suggest that intradermal PRP therapy may be a safe and effective alternative for the treatment of Hori's nevus and can complement conventional interventions. However, further research with a larger sample size, control groups, and longer follow-up is needed to confirm these findings.

Awareness of sun exposure risks and photoprotection for preventing pigmentary disorders in Asian populations: Survey results from three Asian countries and expert panel recommendations

BACKGROUND

In this article, we review and discuss the photoprotection behavior of Asians based on the literature, along with a subanalysis of an original online survey, and make recommendations to optimize photoprotection for Asian populations to prevent photoaging and pigmentary disorders.

METHODS

An international panel of eight dermatologists from Asia (China, Korea, Japan, Singapore, Indonesia, and Vietnam) met to discuss sunscreen photoprotection for Asian patients. Additionally, a subanalysis of an online survey by 3000 respondents from three Asian countries (China, Indonesia, and Japan) investigated general public awareness and attitudes to sun exposure.

RESULTS

A pre-meeting survey of the eight experts from Asia showed key concerns of Asian patients consulting dermatologists are pigmentary disorders, especially actinic/senile lentigo, post-inflammatory hyperpigmentation, melasma, vitiligo, and Hori's nevus. The survey subanalysis of participants from China, Indonesia, and Japan with predominantly Fitzpatrick skin types (FST) II to IV revealed that they are particularly concerned about sun exposure causing photoaging and pigmentary disorders. Most of the respondents indicated they have limited knowledge on sunlight radiation and appropriate sunscreen protection factors. Only 22%, 13%, and 3% for China, Indonesia, and Japan, respectively, systematically use multiple protective measures (using sunscreen, avoiding midday sun, staying in the shade, wearing a hat, protective clothing, and sunglasses) when exposed to the sun.

CONCLUSIONS

Further education is needed for Asian populations on the importance of comprehensive daily photoprotection, including broad-spectrum sunscreen, with high UVA and visible light protection, to reduce and prevent photoaging and pigmentary disorders.

Disorders of Facial Hyperpigmentation

Disorders of hyperpigmentation are common and challenging conditions which can arise due to a myriad of etiologic factors. Many of them can present across skin types but are more common in skin of color individuals with Fitzpatrick skin types III-VI. Facial hyperpigmentation, in particular, can have a significant impact on the quality of life of affected individuals due to its increased visibility. This article provides a comprehensive review of disorders of facial hyperpigmentation including epidemiology, pathogenesis, diagnostic considerations, and treatment approaches for these conditions.

Blue naevi and the blue tumour spectrum

Blue naevi (BN) form a wide group of benign dermal melanocytic proliferations. They are genetically distinct from common and Spitz naevi with frequent hotspot mutations occurring in Gαq genes. Clinically, BN display a female predominance, elective sites of emergence and a great variety of subtypes related to specific regions of the skin linked to early embryological genetic events. Histologically, most BN are located in the dermis with small, bland, spindled and dendritic pigmented melanocytes within a fibrous background. Variation in tumour volume, fibrosis, and melanin pigment load can be broad. A growth in size and cellularity can occur within a subset of tumours as they acquire the morphological features of cellular blue naevi, with a biphasic architecture associating a dendritic blue naevus morphology near the surface, and deep vertical cellular expansions of medium-sized, bland melanocytes often reaching the subcutis. Sclerosing and myxoid variants can be observed either as individual or combined modifications that can add complexity to an otherwise straightforward diagnosis. Malignant progression of a cellular blue naevus is exceptional with an intermediate stage named atypical cellular blue naevus. Malignant blue melanomas are fast growing, large, pigmented tumours with most often obvious features of malignancy. However, they are difficult to separate from other malignant dermal melanocytic proliferations. Herein, we will extensively detail and illustrate the clinical, histological and genetic features of the vast spectrum of blue naevi and related entities in the skin.

A retrospective study of 1064-nm Q-switched Nd:YAG laser therapy for acquired bilateral nevus of Ota-like macules

BACKGROUND

The therapeutic efficacy of laser treatments for acquired bilateral nevus of Ota-like macules (ABNOM) varies among studies, and few studies have evaluated the factors affecting therapeutic effects.

AIMS

To evaluate the efficacy and safety of 1064-nm Q-switched Nd:YAG laser (QSNYL) therapy for ABNOM and to identify the factors influencing the outcome.

METHODS

A total of 110 patients with ABNOM were retrospectively evaluated and received two-to-nine treatment sessions. The effects of different factors on the therapeutic effect were analyzed on the basis of the number of treatments, age at first treatment, skin type, lesion color, affected area, number of lesion sites, and presence of concomitant melasma.

RESULTS

The curative effect was positively correlated with the treatment time and negatively correlated with the increasing age at first treatment (p < 0.05). The curative effect was better in patients with skin type III than those with type IV ( p < 0.05) and in patients with a lesion area of less than 10 cm2 than those with a larger affected area (p < 0.05). Additionally, the treatment effect was poorer in patients with concomitant melasma (p < 0.05). The treatment effect was not significantly correlated with the lesion color or number of affected sites (p > 0.05). Eleven patients (10%) developed postinflammatory hyperpigmentation (PIH).

CONCLUSIONS

Early and repeated QSNYL therapy achieved satisfactory results for ABNOM. The risk of PIH after laser treatment is highest among patients with older age, darker lesion color, and darker skin color. For patients with ABNOM with concurrent melasma, low-energy laser therapy is recommended to reduce the risk of melasma aggravation.

Skin diseases in Asian individuals that you do not want to miss: A selection of unique or relatively more common conditions in Asian populations

The Asian population currently constitutes a simple majority of the global population, comprising nearly 60%. The percentage of the US population that identifies as Asian is expected to grow to 41 million by the year 2050, making up an eventual 9% of the US population. As the world and US populations of Asian individuals increase, the demand for dermatologic care from this population will increase, requiring dermatologists to become more familiar with the diagnosis and treatment of Asian-specific skin characteristics and diseases. In this contribution, we review skin conditions specific to or relatively more common in Asian patients to help recognition and management of diseases in an increasing Asian patient population. We discuss prurigo pigmentosa, primary cutaneous plasmacytosis, lipodystrophia centrifugalis abdominalis infantilis, Epstein-Barr viru-positive T- and natural killer-cell lymphoproliferative disorders, acquired bilateral nevus of Ota-like macules, and Behҫet disease.

Efficacy and safety of 755 nm Q-switched Alexandrite Laser for Hori's nevus: a retrospective analysis of 482 Chinese women

To evaluate the efficacy and safety of 755 nm Q-Switched alexandrite laser for Hori's nevus in a large cohort of Chinese women. We retrospectively analyzed the efficacy and safety of 755 nm Q-Switched alexandrite laser for Hori's nevus. Reduction in pigment was evaluated using a 4-score method. A total of 482 patients, aged 16 to 52 years, were included in this analysis. Patients were treated with 755 nm Q-Switched alexandrite laser at fluence levels of 5-8 J/cm² for 2-4 treatment sessions. Following the treatments, 53% of patients showed over 75% reductions in pigment while 50-75% reductions in pigment were observed in 28% of patients. The rest displayed less than 50% improvements. Efficacy was positively correlated with the number of treatment sessions (p < 0.0001). Adverse reactions were temporary, mild erythema, and edema. A small portion of patients (15%) had hyperpigmentation, which disappeared within 2-6 months. 755 nm Q-Switched alexandrite laser is safe and has moderate benefits for Hori's nevus. Because its efficacy is positively correlated with the number of treatment sessions, increase in treatment sessions possibly could achieve a better outcome.

Both Age and Disease Duration are Associated with Clinical Phenotype of Hori's Nevus in Chinese: A Retrospective Analysis of 497 Cases

Background

Hori’s nevus is a common pigmented disorder on the face, preferentially in females. The clinical features have not been well characterized.

Aim

To characterize the clinical features of Hori’s nevus in Chinese adults.

Subjects and Methods

Data were collected from files of patients who visited our hospital from 2015 to 2018. Age- and disease duration-related characteristics were analyzed.

Results

A total of 497 patients, including 486 females and 11 males, were included in this analysis. One fifth of the patients had a family history of Hori’s nevus. Over 70% of patients were aged 21–30 years. Age at onset was comparable between males and females (20.64 ± 1.01 vs 18.99 ± 0.24). Out of 497 subjects, 218 subjects (44%) displayed yellow-brown lesions while blue-brown lesions wwere observed in 103 subjects (21%). The rest (176 cases, 35%) showed slate-grey lesions. Involvement in the zygomatic area was observed in 496/497 subjects. Involvement in a single area accounted for 74% of patients, while two areas were involved in 19% of patients. The number of involved areas correlated positively with disease duration. However, the proportion of subjects with yellow-brown lesions correlated negatively with disease duration, while the proportion of subjects with slate-grey lesions correlated positively with disease duration. The proportion of subjects with lesions involving the lower eyelids, the root of the nose, the temple and the outer frontal area correlated positively with age.

Conclusion

Hori’s nevus mainly involves the zygomatic area in subjects aged 21–30 years. Lesion color is associated with age, age at onset, and disease duration.

Clinical Evaluation of Safety and Efficacy of a 670-nm Picosecond Laser for Treatment of Benign Pigmented Lesions in Asians

BACKGROUND

Picosecond lasers are increasingly being investigated in treating pigmentation disorders because they may provide better treatment efficacy and comfort compared with nanosecond lasers.

OBJECTIVE

This study aims to evaluate the efficacy and side effect of a novel 670-nm picosecond laser in the removal of benign pigmented lesions (BPLs) in individuals with Fitzpatrick skin types (FST) III and IV.

MATERIALS AND METHODS

Fifteen subjects with solar lentigines and 7 subjects with ABNOMs received a single treatment with a 670-nm picosecond laser. Blinded physicians assessed the pigment clearance using a 5-category grading system scale. All subjects were evaluated at 1 month, 3 month, and 6 month after a single treatment. Adverse events were recorded at every follow-up visit.

RESULTS

All subjects with lentigines had complete clearance (95%-100%) of lesions during 3-month follow-up after a single treatment session of 670-nm picosecond laser, whereas 75% of the subjects with ABNOMs noted fair lightning (25%-49%) of lesions. Mild hypopigmentation and hyperpigmentation were observed in 9% and 14% of the subjects, respectively, which resolved within 3 months after the treatment.

CONCLUSION

The novel 670-nm picosecond laser is a safe and effective treatment for BPLs in subjects with FST III and IV with low rates of transient adverse effects.

Facial Hyperpigmentation in Skin of Color: Special Considerations and Treatment

Differences in cutaneous diseases in people of color call for nuanced evaluation and management. One of the most common dermatological complaints from patients with skin of color is dyspigmentation, particularly hyperpigmentation. The challenge for clinicians is to establish correct diagnoses along with consistently successful treatments to meet the needs of the increasingly diverse population served. This review focuses on facial hyperpigmentation and outlines the most common skin disorders and treatment options.

Acquired dermal melanocytosis of the face and extremities

Acquired dermal melanocytosis (ADM) is a relatively rare, but well-described disease among adolescent to middle-aged East Asian women, particularly those of Japanese and Chinese descent. Clinically, ADM manifests as multiple punctate and greyish-brown pigmented areas 1-3 mm in diameter occurring on both sides of the forehead and zygomatic region. The subtype of ADM affecting the face and extremities is extremely rare even in East Asian women. We describe three patients with ADM of the face and extremities (ADMFE) and their characteristic clinical features. All patients were Japanese women, and showed multiple greyish-brown pigmentations on both nasal wings and on the extensor surface of the extremities. We found that the clinical features were strikingly uniform, and that a pigmented lesion on the nasal wing can be an important clue to distinguish ADMFE from other hyperpigmented diseases of the hands and feet. One patient was treated with Q-switched ruby laser with excellent outcome. Increased awareness of ADMFE can lead to earlier diagnosis and potential treatment.

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

Laser treatment has emerged as a common treatment modality for acquired bilateral nevus of Ota-like macules (ABNOM). To identify the ratio of melasma induction and exacerbation before and after laser therapy for ABNOM and to observe the risk factors related to the induction and exacerbation of melasma by laser therapy, we analyzed related factors of 1268 adult Chinese patients who underwent 1064-nm Q-switched neodymium:yttrium-aluminum-garnet (Nd:YAG) laser (QNYL) treatment using case series and case-control studies. Overall, 24.0% of the ABNOM patients had mixed melasma. Among the ABNOM patients without melasma, after laser therapy the development of melasma was more frequently noted in patients older than 35 years (P < 0.0001), as well in patients whose ABNOM was less than 10 cm(2) (P = 0.027), ABNOM were light (similar to yellow-brown) in color (P = 0.021) and skin types were closer to type IV (P < 0.0001). New melasma lesions also appeared most frequently in the zygomatic region (P < 0.0001). Among the ABNOM patients with melasma, 89.5% experienced worsening of their melasma, irrespective of their related factors above. We concluded that the risk of inducing melasma is great after 1064-nm QNYL treatment in ABNOM patients, and particularly in the patients with both ABNOM and melasma. ABNOM patients should be treated as early as possible and before the age of 35 years.

Acquired Bilateral Nevus of ota-like Macules with Mucosal Involvement: A New Variant of Hori's Nevus

Acquired bilateral nevus of Ota-like macules (ABNOM) or Hori's nevus, a rare form of acquired dermal melanocytoses, presents as bilateral facial blue-gray macules without ocular or mucosal involvement. This condition is mostly found in women of Asian descent and usually appears in the fourth or fifth decade of life. Pathogenesis is unknown, though few theories have been proposed. Effective treatment has been found to be achieved with pigment-specific lasers. Herein, we report a case of Hori's nevus with mucosal involvement. A 42-year-old male patient, presented to us with blue-gray discoloration on either side of his face, both eyes, and in the mouth since the age of one year. Histopathological examination showed clusters and singly dispersed pigmented melanocytes within the upper and mid-dermis regions. Special staining of melanocytes using Masson-Fontana stain was positive. Diagnosis of Hori's nevus was made by correlating clinical and histopathological findings. Patient was informed of his treatment options, but refused treatment. A similar case of Hori's nevus with mucosal involvement has not been reported so far.

Eponyms, morphology, and pathogenesis of some less mentioned types of melanocytic nevi

Some types of melanocytic nevi are seldom mentioned in the literature and are therefore less well known. In the current study, we focus on the concepts of eponyms, synonyms, clinical presentation, and morphology of the following types: Meyerson nevus, cockarde (or cockade) nevus, Hori nevus, Sun nevus, Hidanos nevus, Duperrat nevus, Spark nevus, nevus spilus, eclipse nevus, Kerl nevus, and Kopf nevus.

Gender aspects in skin diseases

Gender differences in medicine have been recognized in anatomy, physiology, as well as in epidemiology and manifestations of various diseases. With respect to skin disorders, males are generally more commonly afflicted with infectious diseases while women are more susceptible to psychosomatic problems, pigmentary disorders, certain hair diseases, and particularly autoimmune as well as allergic diseases. Significantly, more female sex-associated dermatoses can be identified than the male sex-associated dermatoses. Dermatoses in the genital area differ between men and women. Gender differences also exist in the occurrence and prognosis of certain skin malignancies. The mechanisms underlying gender differences in skin diseases remain largely unknown. Differences in the skin structure and physiology, effect of sex hormones, ethnic background, sociocultural behaviour and environmental factors may interact to exert the influences. A better understanding of gender differences in human health and diseases will allow the development of novel concepts for prevention, diagnosis and therapy of skin diseases.

Q-Switched Nd:YAG Laser Therapy of Acquired Bilateral Nevus of Ota-like Macules

BACKGROUND

Acquired bilateral nevus of Ota-like macules (ABNOM) is a dermal pigmented lesion common in individuals of Oriental origin. The Q-switched Nd:YAG laser (QSNYL) has been used successfully to treat a variety of benign, dermal, pigmented lesions, including nevus of Ota lesions. The similarity between ABNOM and nevus of Ota suggested that QSNYL may also be effective in the former.

OBJECTIVE

To determine the efficacy and side-effect profiles of QSNYL treatment of ABNOM in Korean patients.

METHODS

Of 42 Korean patients with ABNOM, 29 were treated with QSNYL (1,064 nm, 3 mm spot size, fluence 8~9.5 J/cm(2)), for up to 10 sessions each. Clinical photographs were taken before and after treatment. Lesion clearance was graded and complications such as hyperpigmentation, scarring, hypopigmentation, and erythema were assessed.

RESULTS

Of the 29 treated patients, 19 (66%) showed excellent or good results. Of the patients who were treated more than 3 times, 76% showed good to excellent results. Two patients experienced post-laser hyperpigmentation (PLH), which persisted for more than one month, but no patient experienced persistent erythema or hypertrophic scarring.

CONCLUSION

QSNYL is safe and effective in the treatment of ABNOM in Korean patients. Short-interval repetitive treatment is especially useful in improving therapeutic results and reducing PLH.

Late-onset Ito?s nevus: An uncommon acquired dermal melanocytosis

Dermal melanocytoses comprise a variety of congenital and acquired conditions characterized by a sparse population of intradermal dendritic, variably pigmented, spindle-shaped melanocytes. While Mongolian spot, Ota's and Ito's nevi are usually present at birth or appear around puberty; acquired dermal melanocytoses that appear in adult life are extremely rare. They include the facial lesions of acquired bilateral nevus of Ota-like macules, also named Hori's nevus, and the acquired unilateral nevus of Ota, also known as Sun's nevus. Uncommon extrafacial examples of acquired dermal melanocytoses include lesions involving upper extremities, wrist, back, lower extremities and dorsal aspects of the hands and feet. They are more prevalent among Asian women. In general, dermal melanocytoses are rare lesions in Caucasian patients and acquired variants are exceedingly uncommon. We report a rare example of acquired Ito's nevus that appeared in a Caucasian elderly woman and review the literature about acquired dermal melanocytoses.

Diagnosis and Treatment of Pigmentary Disorders in Asian Skin

Individuals of Asian heritage are predisposed to congenital and acquired pigmentary disorders. Cosmetic enhancement is frequently the primary treatment goal for these benign lesions. Accurate diagnosis of the nature of the pigmentary disorder is fundamental for administering safe and effective therapy. Before the advent of modern laser technology, such reported treatments as cryotherapy, dermabrasion, chemical peeling, and surgical excision resulted in unpredictable results. This article focuses on the diagnosis of disorders of pigmentation in Asian patients and reviews laser and light treatment modalities.