Nada Elbuluk

Alteration in the gene encoding protein tyrosine phosphatase nonreceptor type 6 (PTPN6/SHP1) may contribute to neutrophilic dermatoses.

We have found a B2 repeat insertion in the gene encoding protein tyrosine phosphatase nonreceptor type 6 (PTPN6) in a mouse that developed a skin disorder with clinical and histopathological features resembling those seen in human neutrophilic dermatoses. Neutrophilic dermatoses are a group of complex heterogeneous autoinflammatory diseases that all demonstrate excessive neutrophil infiltration of the skin. Therefore, we tested the cDNA and genomic DNA sequences of PTPN6 from patients with Sweets syndrome (SW) and pyoderma gangrenosum and found numerous novel splice variants in different combinations. Isoforms resulting from deletions of exons 2, 5, 11, and 15 and retention of intron 1 or 5 were the most common in a patients with a familial case of SW, who had a neonatal onset of an inflammatory disorder with skin lesions and a biopsy specimen consistent with SW. These isoforms were associated with a heterozygous E441G mutation and a heterozygous 1.7-kbp deletion in the promoter region of the PTPN6 gene. Although full-length PTPN6 was detected in all other patients with either pyoderma gangrenosum or SW, it was always associated with splice variants: a partial deletion of exon 4 with the complete deletion of exon 5, alterations that were not detected in healthy controls. The defect in transcriptional regulation of the hematopoietic PTPN6 appears to be involved in the pathogenesis of certain subsets of the heterogeneous group of neutrophilic dermatoses.

Alternative Systemic Treatments for Vitiligo: A Review

Vitiligo is a common, acquired disorder of skin pigmentation that can significantly impact quality of life. It often represents a therapeutic challenge, which has resulted in interest in alternative treatments such as herbal and vitamin supplements. In this review, we provide an overview of the most commonly studied complementary agents, describe proposed mechanisms of action, identify potential adverse effects, and discuss the primary evidence supporting their use. Our discussion focuses on l-phenylalanine, Polypodium leucotomos, khellin, Ginkgo biloba, and vitamins and minerals, including vitamins B12, C, and E, folic acid, and zinc used as monotherapy or in combination with other treatments for the management of vitiligo.

Recent advances in understanding vitiligo

Vitiligo, an acquired depigmentation disorder, manifests as white macules on the skin and can cause significant psychological stress and stigmatization. Recent advances have shed light on key components that drive disease onset and progression as well as therapeutic approaches. Vitiligo can be triggered by stress to the melanin pigment-producing cells of the skin, the melanocytes. The triggers, which range from sunburn to mechanical trauma and chemical exposures, ultimately cause an autoimmune response that targets melanocytes, driving progressive skin depigmentation. The most significant progress in our understanding of disease etiology has been made on three fronts: (1) identifying cellular responses to stress, including antioxidant pathways and the unfolded protein response (UPR), as key players in disease onset, (2) characterizing immune responses that target melanocytes and drive disease progression, and (3) identifying major susceptibility genes. The current model for vitiligo pathogenesis postulates that oxidative stress causes cellular disruptions, including interruption of protein maturation in the endoplasmic reticulum (ER), leading to the activation of the UPR and expression of UPR-regulated chemokines such as interleukin 6 (IL-6) and IL-8. These chemokines recruit immune components to the skin, causing melanocytes to be targeted for destruction. Oxidative stress can further increase melanocyte targeting by promoting antigen presentation. Two key components of the autoimmune response that promote disease progression are the interferon (IFN)-γ/CXCL10 axis and IL-17-mediated responses. Several genome-wide association studies support a role for these pathways, with the antioxidant gene NRF2, UPR gene XBP1, and numerous immune-related genes including class I and class II major histocompatibility genes associated with a risk for developing vitiligo. Novel approaches to promote repigmentation in vitiligo are being investigated and may yield effective, long-lasting therapies.

Microneedling: A Comprehensive Review.

BACKGROUND Microneedling is a minimally invasive procedure that uses fine needles to puncture the epidermis. The microwounds created stimulate the release of growth factors and induce collagen production. The epidermis remains relatively intact, therefore helping to limit adverse events. The indications for microneedling therapy have grown significantly, and it is becoming a more widely used treatment in dermatology. OBJECTIVE A comprehensive review of microneedling in human subjects and its applications in dermatology. METHODS AND MATERIALS A search was performed using PubMed/MEDLINE and Science Direct databases. Search terms included “microneedling,” “needling,” and “percutaneous collagen induction.” All available studies involving human subjects were included in the discussion, with priority given to prospective, randomized trials. RESULTS Studies demonstrate microneedling efficacy and safety for the treatment of scars, acne, melasma, photodamage, skin rejuvenation, hyperhidrosis and alopecia and for facilitation of transdermal drug delivery. While permanent adverse events are uncommon, transient erythema and postinflammatory hyperpigmentation are more commonly reported. CONCLUSION Microneedling appears to be an overall effective and safe therapeutic option for numerous dermatologic conditions. Larger and more randomized controlled trials are needed to provide greater data on the use of microneedling for different dermatologic conditions in different skin types.

Melasma: an Up-to-Date Comprehensive Review

Melasma is a common acquired condition of symmetric hyperpigmentation, typically occurring on the face, with higher prevalence in females and darker skin types. Multiple etiologies, including light exposure, hormonal influences, and family history, have been implicated in the pathogenesis of this disorder. Overall prevalence ranges widely at 1–50%, since values are typically calculated within a specific ethnic population within a geographic region. Histologically, melasma can display increased epidermal and/or dermal pigmentation, enlarged melanocytes, increased melanosomes, solar elastosis, dermal blood vessels, and, occasionally, perivascular lymphohistiocytic infiltrates. Various topical, oral, and procedural therapies have been successfully used to treat melasma. Traditional topical therapies including hydroquinone, tretinoin, corticosteroids, and triple combination creams; however, other synthetic and natural topical compounds have also shown varying efficacies. Promising oral therapies for melasma include tranexamic acid, Polypodium leucotomos, and glutathione. Procedures, including chemical peels, microneedling, radiofrequency, and lasers, are also often used as primary or adjunctive treatments for melasma. Notably, combination therapies within or across treatment modalities generally result in better efficacies than monotherapies. This review serves as a comprehensive update on the current understanding of the epidemiology, pathogenesis, clinical and histologic features of melasma, as well as treatments for this common, yet therapeutically challenging, condition.

Quality of Life, Burden of Disease, Co-morbidities, and Systemic Effects in Vitiligo Patients

Vitiligo is a complex, systemic disease associated with many autoimmune and autoinflammatory conditions. Additionally, the cutaneous changes of vitiligo have significant effects on quality of life and self-esteem. Further efforts are needed to increase our understanding of vitiligo comorbidities as well as to increase awareness of the psychological effects of vitiligo.

Retinoic acid 4-hydroxylase inducibility and clinical response to isotretinoin in patients with acne

BACKGROUND The cytochrome P450 (CYP) enzyme CYP26 (retinoic acid [RA] 4-hydroxylase) initiates the catabolism of all-trans RA (tRA) and limits the effects of tRA. The CYP26 enzyme acts specifically on tRA, but not 13-cis RA (isotretinoin), a retinoid used to treat severe acne. However, 13-cis RA can isomerize to tRA, which can then be metabolized by CYP26. OBJECTIVE In healthy individuals, we assessed the variability of CYP26 enzymatic activity. We then investigated whether response to oral 13-cis RA among patients with acne correlates with variability in CYP26 expression. METHODS In healthy individuals, we isolated microsomal fractions from the epidermis of keratome biopsy specimens and measured CYP26 enzymatic activity in untreated skin and skin treated with tRA. Enzymatic activity was determined based on rate of formation of 4-hydroxy RA (pg/min/mg microsomal protein). Using real-time polymerase chain reaction we quantified CYP26 messenger RNA induction after tRA application in patients with acne who responded or did not respond to one course of 13-cis RA. RESULTS In normal-appearing skin (N = 118), CYP26 enzymatic activity was widely variable (1-180 pg/min/mg microsomal fraction; mean 42.7 +/- 3.5). Furthermore, CYP26 enzymatic activity was inducible in a dose-dependent manner in normal-appearing skin after tRA application, but not correlated with age or sex (N = 29). In patients with acne, CYP26 messenger RNA induction after 0.1% tRA application did not differ (P > .05) between patients who responded (N = 8, 587 +/- 325-fold) or did not respond (N = 8, 657 +/- 227-fold) to one course of 13-cis RA. LIMITATIONS The small number of patients with acne treated with 13-cis RA was a major limitation. CONCLUSION Factors other than CYP26 activity may determine response to isotretinoin in acne.

Daily indoor light exposure: A spectral analysis of ambient light sources and its relevance to occupational dermatology

Fig 1. A, iPhone 6 Plus white background, brigh iPad Pro, white background, brightness 100%, 1 emitting diode television screen, brightness 100% display desktop monitor, brightness 100%, 1 cm fr desktop monitor, maximized exposure integration deep infrared range are artefactual and not real. G was very small (as demonstrated above), in order exposure integration time and zoom in on the disp ends). F, Dell liquid crystal display laptop screen, spectral signatures of ambient indoor light sources that surround people routinely during activities of daily living. Spectra irradiance curves were recorded using a calibrated spectrometer (BLK C-SR XYZ123 UV-V spectrometer; StellarNet Inc, Tampa, FL). We analyzed various common sources of visible light encountered on a daily basis within the ambulatory care clinics and offices in the department of dermatology at our academic institution. We analyzed smartphones (Apple iPhone 6 Plus; Apple Inc, Cupertino, CA), tablets (Apple iPad Pro, Apple Inc), computer desktop monitors (Dell LCD monitor P2414HB; Dell Inc, Round Rock, TX), laptop screens (Dell Inspiron 15 3000 series; Dell Inc), large flatscreen televisions used for display (Sharp Aquos LC70LE745U, Sharp Electronics Corporation, Tokyo, Japan), office ceiling lights (Pentron 3500k 28w fp28/ 835/eco; OSRAM Sylvania, Wilmington, MA), clinic examination room ceiling lights (Pentron 3500k 28w fp28/835/eco, OSRAM Sylvania), office desktop lamps (CF23EL/mini, 2700K, OSRAM Sylvania), and

The nuclear factor (erythroid-derived 2)-like 2 (NRF2) antioxidant response promotes melanocyte viability and reduces toxicity of the vitiligo-inducing phenol monobenzone

Vitiligo, characterised by progressive melanocyte death, can be initiated by exposure to vitiligo‐inducing phenols (VIPs). VIPs generate oxidative stress in melanocytes and activate the master antioxidant regulator NRF2. While NRF2‐regulated antioxidants are reported to protect melanocytes from oxidative stress, the role of NRF2 in the melanocyte response to monobenzone, a clinically relevant VIP, has not been characterised. We hypothesised that activation of NRF2 may protect melanocytes from monobenzone‐induced toxicity. We observed that knockdown of NRF2 or NRF2‐regulated antioxidants NQO1 and PRDX6 reduced melanocyte viability, but not viability of keratinocytes and fibroblasts, suggesting that melanocytes were preferentially dependent upon NRF2 activity for growth compared to other cutaneous cells. Furthermore, melanocytes activated the NRF2 response following monobenzone exposure and constitutive NRF2 activation reduced monobenzone toxicity, supporting NRF2s role in the melanocyte stress response. In contrast, melanocytes from individuals with vitiligo (vitiligo melanocytes) did not activate the NRF2 response as efficiently. Dimethyl fumarate‐mediated NRF2 activation protected normal and vitiligo melanocytes against monobenzone‐induced toxicity. Given the contribution of oxidant‐antioxidant imbalance in vitiligo, modulation of this pathway may be of therapeutic interest.

Differences in Skin Structure and Function in Ethnic Populations

The structure and function of the various components of skin are well studied. In the last few decades, increasing research has examined whether the structure and function of skin may vary among skin types including those across different races and ethnicities. Certain similarities and differences have been discovered while other areas require further study. As physicians continue to treat diverse populations, an understanding of these similarities and differences is essential in providing appropriate medical care.