Psoriasis is a chronic inflammatory systemic disease primarily affecting the skin, but which often involves considerable comorbidities as well. One-third of psoriasis cases start during childhood. In pediatric psoriasis, an association with several medical comorbidities is also indicated. Furthermore, because of its chronic nature and frequent relapses, psoriatic patients tend to require long-term treatment and experience negative impacts on their quality of life. Considering the different clinical characteristics of pediatric psoriasis, it has recently been presented that the pathogenesis of pediatric psoriasis is distinct from adult psoriasis. Treatment for pediatric psoriasis usually involves the same methods as for adults. However, most treatments in pediatric psoriasis are used off-label and research in this regard is still lacking. Targeted therapies involving newly developed biologics are also increasingly being applied to psoriasis in children. This review summarizes the clinical characteristics of pediatric psoriasis and focuses mainly on the updated concepts of pathogenesis and treatments in pediatric psoriasis. This was undertaken to widen the understanding of these relevant aspects and to provide better management of pediatric psoriasis by clinicians.

Recently, the mTOR signaling has emerged as an important player in the pathogenesis of psoriasis. We previously found that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced psoriatic skin inflammation was related to the inhibition of autophagy in keratinocytes. However, the effects and detailed molecular mechanisms of the mTOR inhibitor rapamycin and TCDD on psoriasis in vivo remain to be elucidated. In this study, we aimed to evaluate the effects of rapamycin and TCDD on skin lesions in imiquimod (IMQ)-induced psoriasis using a mouse model. TCDD aggravated skin inflammation in an IMQ-induced psoriatic mouse model. Furthermore, TCDD increased the expression of aryl hydrocarbon receptor (AHR), CYP1A1, proinflammatory cytokines, oxidative stress markers (NADPH oxidase (Nox) 2, Nox4), and phosphorylated P65NF-ĸB, whereas the expression of autophagy-related factors and the antioxidant marker nuclear factor-erythroid 2-related factor 2 (NRF2) decreased. Rapamycin reduced the aggravated skin inflammation induced by TCDD and restored TCDD-induced autophagy suppression and the increase of AHR expression, oxidative stress, and inflammatory response in the skin lesions of a psoriatic mouse model. In conclusion, we demonstrated that rapamycin alleviates TCDD-induced aggravated dermatitis in mice with imiquimod-induced psoriasis-like dermatitis through AHR and autophagy modulation.

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Background and Objective: Little is known about the anti-pigmentation effects of whitening agents on solar lentigines. Epidermal growth factor (EGF) has been used as a booster for wound healing in the skin, and it has been suggested to have anti-pigmentation effects. This study aimed to evaluate the effect and safety of EGF-containing ointment for treating solar lentigines with a Q-switched (QS) 532 nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser (Bluecore company, Seoul, Republic of Korea). Materials and Methods: Subjects who underwent QS 532 nm Nd:YAG laser treatment of solar lentigines were randomly assigned to treatment with an EGF ointment or petrolatum. After the laser procedure, the subjects were administered the test ointment twice a day for 4 weeks. The physician’s assessment of the degree of pigment clearance and patient’s satisfaction were assessed after 4 and 8 weeks. Additionally, the melanin index (MI), erythema index (EI), transepidermal water loss (TEWL), and post-inflammatory hyperpigmentation (PIH) were evaluated. This trial was registered with ClinicalTrials.gov (NCT04704245). Results: The blinded physician’s assessment using 5-grade percentage improvement scale and patient’s satisfaction were significantly higher in the study group than in the control group at the 4th and 8th weeks. The MI was significantly higher in the control group than in the study group at the 4th and 8th weeks. The EI and TEWL did not differ significantly between the two groups at either time point. The incidence of PIH was higher in the control group (37.5%) than in the EGF group (7.14%) at the 8th week. Conclusions: The application of EGF-containing ointment on facial solar lentigines with a QS 532 nm Nd:YAG laser showed efficient and safe therapeutic effects, with less PIH. Thus, EGF-containing ointment could be suggested as the promising adjuvant treatment strategy with a QS laser for solar lentigines.

Various methods have been used for scar prevention; however, the optimal method remains unclear. We investigated the efficacy of combinational intense pulsed light (IPL)/fractional erbium‐doped yttrium aluminum garnet (Er:YAG) laser treatment in early wound healing. This was a prospective, randomized, controlled split wound trial. Scars were divided into three sites: the combined IPL/fractional Er:YAG treatment, fractional Er:YAG laser treatment, and untreated control sites. Treatment was conducted in three sessions: at removal of stitches and after 4 and 8 weeks. Treatment efficacy was evaluated using the Patient Observer Scar Assessment Scale (POSAS) and Vancouver Scar Scale (VSS) scores. The erythema index (EI) and melanin index (MI) were measured. In the total POSAS score, the IPL/fractional Er:YAG site showed steady and significant improvement, in contrast to the other sites. At week 8, the combined treatment sites had better POSAS scores than the fractional Er:YAG laser alone sites (p = 0.001) and the control sites (p = 0.000). The effect of combinational treatment was maintained until the follow‐up period by comparing the Er:YAG (p = 0.015) and control sites (p = 0.007). In terms of VSS scores, the IPL/fractional Er:YAG combined treatment sites had consistent improvement at week 8 (p = 0.005) and week 20 (p = 0.02) compared to that at week 4, while the other sites showed no such improvement. In conclusion, the combination of IPL and Er:YAG showed more favorable effects on scar prevention than Er:YAG or no treatment. IPL/Er:YAG therapy could be an effective and safe strategy in the early wound healing process for reducing scar formation.