Melanogenic Properties and Expression Profiles of Melanogenic Paracrine Molecules in Riehl's Melanosis

A novel treatment for Riehl's melanosis targeting both dermal melanin and vessels

BACKGROUND/PURPOSE

Riehl's melanosis is a difficult-to-treat condition characterized by persisting dermal hyperpigmentation. This study aimed to evaluate the efficacy of a histology-specific targeted therapy for Riehl's melanosis.

METHODS

Skin biopsy samples of Riehl's melanosis were assessed to identify histology-specific targets for treatment. Subsequently, the efficacy of a combination involving a fractional picosecond laser and a pulsed dye laser (PDL) targeting the dermal melanin and vessels, respectively, was evaluated. Clinical improvement was assessed using the dermal pigmentation area and severity index (DPASI). The treatment outcomes were compared to those of a control, in this case a single laser treatment solely targeting pigmentation.

RESULTS

Histological and immunohistochemical analyses identified dermal melanin pigment and dilated vessels as treatment targets for Riehl's melanosis. The combined treatment of the fractional picosecond laser and PDL showed a significant reduction of the DPASI scores, which was significantly better than the control group. Patients who underwent the combined laser treatment indicated high levels of satisfaction with no adverse events except of transient erythema and oedema.

CONCLUSION

The combined treatment of a fractional picosecond laser and a PDL was more effective for Riehl's melanosis compared to single laser treatment. The treatment targets both dermal pigmentation and dilated vessels, offering promising results for those working to manage Riehl's melanosis.

Unveiling the mystery of Riehl's melanosis: An update from pathogenesis, diagnosis to treatment

Riehl's melanosis is a hyperpigmentation disorder that has a significant psychological and social impact on individuals. In the past 10 years, new categories have been developed, raising questions about how to classify Riehl's melanosis. The mechanism of this disease remains unclear, although the type IV hypersensitivity response caused by allergic sensitization, as well as genetic, ultraviolet radiation, and autoimmune factors, is to blame. Clinical manifestation, dermoscopy, reflectance confocal microscopy, patch/photopatch testing, histopathology, and a novel multimodality skin imaging system have been used for the diagnosis. A variety of therapies including topical skin-lightening agents, oral tranexamic acid, glycyrrhizin compound, chemical peels, and lasers and light therapies (intense pulsed light, 1064-nm Q-Switched Nd: YAG laser, 755-nm PicoWay laser, nonablative 1927-nm fractional thulium fiber laser, new pulsed-type microneedling radiofrequency), with improved effectiveness. The latest findings on possible biomarkers and their relationship to other autoimmune diseases were also summarized.

Research Advances in the Treatment of Riehl's Melanosis

Riehl's melanosis (RM) is a contact photodermatitis, with fast progressive gray-brown skin pigmentation as the main manifestation, which can seriously affect the psychology and physiology of patients. Currently, although the etiological factors of Riehl's melanosis is still be unknown, the existing literature proves clearly the cause of it is related to the contacting with suspected allergens. For decades, there has been no standard method for the treatment of RM, but with both conventional drug therapy and laser therapy having been attempted. Topical application of bleaching agents is mainly used as an auxiliary treatment modality. The laser treatment modality remains a hot spot, among which Q-switched Nd:YAG laser is well received for RM. Positive outcomes have been achieved by the combined treatment modalities attempted in recent years also achieve positive outcomes. The purpose of this paper is to review and summarize recent advances in the treatment of the disease.

Advances in Biomedical Functions of Natural Whitening Substances in the Treatment of Skin Pigmentation Diseases

Pigmentation diseases can lead to significant color differences between the affected part and the normal part, resulting in severe psychological and emotional distress among patients. The treatment of pigmentation diseases with good patient compliance is mainly in the form of topical drugs. However, conventional hydroquinone therapy contributes to several pathological conditions, such as erythema, dryness, and skin desquamation, and requires a longer treatment time to show significant results. To address these shortcomings, natural whitening substances represented by kojic acid and arbutin have gradually become the candidate ingredients of traditional local preparations due to their excellent biological safety. This review focuses on several natural whitening substances with potential therapeutic effects in pigmentation disease and their mechanisms, and a thorough discussion has been conducted into the solution methods for the challenges involved in the practical application of natural whitening substances.

Riehl’s Melanosis: A Multimodality, In Vivo, Real-Time Skin Imaging Study with Cellular Resolution Optical Coherence Tomography and Advanced Skin Diagnosis System in a Tertiary Medical Center

Background: Riehl’s melanosis is a psychologically devastating hyperpigmentary disorder that typically occurs on the face and neck. The study of Riehl’s melanosis is limited due to its rarity, variable morphology, and lack of noninvasive diagnostic tools. Recent advances in skin imaging analysis and diagnostic systems improve diagnostic accuracy and enable the noninvasive, real-time evaluation of pigmentary disease. A comprehensive study of Riehl’s melanosis clinical morphology with multimodality and in vivo skin imaging systems has yet to be reported. Objectives: To investigate the clinical features and in vivo advanced skin imaging findings of Riehl’s melanosis. Methods: We retrospectively investigated the clinical characteristics, dermoscopic, and histopathological features of Riehl’s melanosis. We further utilized multimodality skin imaging analysis systems, including a cellular resolution optical coherence tomography (OCT) and new skin diagnosis system, to investigate the features of Riehl’s melanosis. In addition, we compared OCT findings with histopathological features and clinical assessment. Results: We evaluated 30 patients with Riehl’s melanosis at a tertiary medical center from 2010 to 2022. The average age was 47.7 ± 12.3 (mean ± SD) years, predominantly female patients (female: n = 23; male: n = 7). Cellular resolution OCT imaging from lesion skin shows increased melanocyte capping, disrupted basement membrane, telangiectatic blood vessels, and melanophages in the dermis. The advanced skin diagnosis system captured subclinical erythema of the skin, highlighting the inflammatory nature of the disease. The results correlated well with histopathological findings. Limitations: This is a single-center, cross-sectional study. Conclusions: We highlight the features of Riehl’s melanosis through a novel cellular resolution OCT and photographic skin diagnosis system. A multimodality skin diagnosis system can serve as a real-time, in vivo, noninvasive method for evaluating pigmentary disorders.

Therapeutic Effects of New Pulsed-Type Microneedling Radiofrequency for Refractory Facial Pigmentary Disorders

BACKGROUND

Numerous treatments for pigmentary disorders have been used with variable outcomes. Recently, a new radiofrequency (RF) device with minimal pulse duration has been introduced.

OBJECTIVE

The aim of this study was to evaluate the efficacy and safety of a pulsed-type microneedling RF device for treatment of facial pigmentary disorders.

METHODS

Forty-four patients diagnosed with facial melasma or Riehl melanosis received 5 treatments with RF at 2-week intervals, and evaluation was performed at each visits, including 4 and 8 weeks after the last treatment. Treatment outcomes were evaluated by investigator global assessment, patient global assessment score, and skin biophysical parameters of erythema index, melanin index (MI), and transepidermal water loss. Gene array and immunohistochemical staining including melan-A, Fontana silver, CD44, basic fibroblast growth factor (bFGF), and periodic acid-Schiff were performed.

RESULTS

Most of the patients showed clinical improvement. Erythema index, MI, and transepidermal water loss decreased after the first treatment. Histopathologic examination showed decrease of melanin pigment, melanophages, and blood vessel proliferation but thickened basement membrane after treatment. Expression of CD44 and b-FGF was decreased after treatment. There were no serious adverse events reported during the study.

CONCLUSION

Pulsed-type microneedling RF could be a treatment option for facial pigmentary disorders.