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Background and objectives The treatment of Riehl's melanosis, also known as pigmented contact dermatitis, is highly challenging. Intense pulsed light (IPL) and 1064 nm Q-switched Nd:Yag (QS-Nd:YAG) laser are reported to have some efficacy. However, no single effective treatment has yet been identified. In this study, we demonstrated the efficacy and safety of the non-ablative 1927 nm fractional thulium fiber laser (TFL, LASEMD™; Lutronic Corp., Goyang, Korea) for patients with Riehl's melanosis. Study design/materials and methods A retrospective chart and photographic review of nine patients with Riehl's melanosis, who had received at least three sessions of TFL treatment, was performed. Before the start of TFL treatment, combination treatment with a topical cream containing hydroquinone, low-fluence QS-Nd:YAG laser, pulsed dye laser, and IPL was used with variable and discouraging effects. Seven patients were treated on the face and two patients on the neck with three to seven sessions at 1-month intervals. Clinical improvement was assessed using clinical photos taken before and after every treatment session according to dermal pigmentation area and severity index (DPASI) and a quartile grading scale by two blinded dermatologists. Results Patients underwent three to seven sessions of TFL treatment depending on severity of pigmentation. Of nine patients, six demonstrated a clinical improvement of 51%-75%, one demonstrated an improvement of 76%-100%, and two showed an improvement of 26%-50% after treatment. The DPASI was significantly decreased from 9.55 to 5.25 on average. Melanin index was decreased after treatment in two patients whose melanin index were measured at initial visits. Treatment-related adverse events, such as scarring or postinflammatory hyperpigmentation (PIH), were not observed in all patients except for transient erythema and swelling. Conclusions This report suggests that TFL could be an alternative and/or additive treatment option for hyperpigmentation in intractable Riehl's melanosis and might be a promising treatment for PIH caused by any reason including Riehl's melanosis. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Autophagy regulates cellular turnover by disassembling unnecessary or dysfunctional constituents. Recent studies demonstrated that autophagy and its regulators play a wide variety of roles in melanocyte biology. Activation of autophagy is known to induce melanogenesis and regulate melanosome biogenesis in melanocytes. Also, autophagy induction was reported to regulate physiologic skin color via melanosome degradation, although the downstream effectors are not yet clarified. To determine the role of autophagy as a melanosome degradation machinery, we administered several autophagy inducers in human keratinocytes and melanocytes. Our results showed that the synthetic autophagy inducer PTPD-12 stimulated autophagic flux in human melanocytes and in keratinocytes containing transferred melanosomes. Increased autophagic flux led to melanosome degradation without affecting the expression of MITF. Furthermore, the color of cell pellets of both melanocytes and keratinocytes was visibly lightened. Inhibition of autophagic flux by chloroquine resulted in marked attenuation of PTPD-12-induced melanosome degradation, whereas the expression of melanogenesis pathway genes and proteins remained unaffected. Taken together, our results suggest that the modulation of autophagy can contribute to the regulation of melanocyte biology and skin pigmentation.

Severe alopecia areata (AA) can have an unpredictable clinical course and become refractory to contact immunotherapy. Novel treatment options include low-dose interleukin-2 and Janus kinase inhibitors; however, these treatments are still under investigation. Therefore, we evaluated the efficacy and safety of intramuscular (i.m.) triamcinolone acetonide (TAC) as a rescue therapy for refractory AA. We retrospectively analysed efficacy, adverse effects and relapse rate of i.m. TAC monthly in 27 patients with refractory AA. We defined AA as refractory if the patient showed an unsatisfactory response to both systemic treatment (not i.m. TAC) and the consecutive diphenylcyclopropenone immunotherapy. The initial systemic treatment of other forms of corticosteroids and/or cyclosporin was used to control extensive AA involving more than 25% of the scalp. Administration of i.m. TAC for 3-6 months resulted in a 63.0% response rate, and all patients showed inactive disease after treatment. Final hair regrowth negatively correlated with initial scalp involvement (Spearman r = -0.595, P = 0.001). All patients showed complete recovery of adrenocortical reserve within 3 months after the last injection. Adverse effects of systemic steroid therapy were observed only in female patients (dysmenorrhea and osteoporosis). i.m. TAC may provide a valuable therapeutic option to manage active hair loss and facilitate hair regrowth in refractory AA, especially in male patients.