Faculty Bibliography

Interfollicular epidermal melanocytes are continually subjected to environmental challenges and activate protective stress responses for survival. Dysregulation of these responses may increase susceptibility to depigmentation typical of chemical leukoderma (depigmentation limited to site of exposure) and vitiligo (progressive depigmentation due to an autoimmune response). We delineated the response of melanocytes from normally pigmented individuals (NMs) to challenge with the chemotoxins monobenzone (MBEH) and 4-tertiary butyl phenol (4-TBP) and determined that the unfolded protein stress response (UPR) was activated following exposure. The UPR, a key survival pathway, is activated when the homeostasis of the Endoplasmic Reticulum (ER) is disrupted, for example by cellular oxidative stress induced by chemotoxin exposure. The UPR, which consists of three signal transduction pathways initiated by PERK, IRE1 or ATF6 respectively, promotes restoration of ER homeostasis and survival. In this study, we assessed the cytoprotective effect of the PERK arm of the UPR. PERK phosphorylates a number of proteins including the eukaryotic translation initiation factor, eIF2alpha. We treated melanocytes with the PERK kinase inhibitor GSK2606414 and confirmed efficacy by monitoring eIF2alpha phosphorylation, which was reduced after treatment. Melanocytes were then dosed with MBEH in the presence or absence of GSK2606414. The inhibitor sensitized melanocytes to MBEH (Cleaved/c-PARP observed with 250 muM MBEH + GSK2606414, compared to 400 muM MBEH + vehicle). To further investigate the role of PERK in melanocytes, we used a gene silencing (shRNA) approach to knockdown expression. An 88% decrease in viability (p < 0.0001) was observed 3 days post-infection (shPERK versus scrambled/shNT). Cultures were maintained for 14 days when viability was found to be improved (40% decrease in viability, p < 0.0001). Melanocytes that survived prolonged PERK downregulation adapted and could be maintained in culture (shPERKLT). Survival correlated with a paradoxical increase in phospho-eIF2alpha and reduced sensitivity to MBEH (c-PARP observed with 500 muM MBEH in shPERKLT versus 400 muM MBEH in shNT cells). Intriguingly, while eIF2alpha is not typically phosphorylated in unstressed cells, a fraction of eIF2alpha was phosphorylated in melanocytes at baseline. Thus PERK may play a role in determining melanocyte viability and sensitivity to chemotoxins

Well-known causes of zinc deficiency, also referred to as acrodermatitis enteropathica (AE), include defects in intestinal zinc transporters and inadequate intake, but a rare cause of acquired zinc deficiency discussed here is an iatrogenic nutritional deficiency caused by parenteral nutrition administered without trace elements. While zinc-depleted parenteral nutrition causing dermatosis of acquired zinc deficiency was first reported in the 1990s, it is now again relevant due to a national vitamin and trace element shortage. A high index of suspicion may be necessary to diagnose zinc deficiency, particularly because early clinical findings are nonspecific. We present this case of acquired zinc deficiency in a patient admitted to a pediatric intensive care unit for respiratory distress and atypical pneumonia, who subsequently developed a severe bullous eruption due to iatrogenic zinc deficiency but was treated effectively with enteral and parenteral zinc supplementation, allowing for rapid re-epithelialization of previously denuded skin.

Tinea incognito (TI) describes a common dermatophytosis with often atypical clinical features attributed to inappropriate use of topical immunomodulatory agents, usually corticosteroids. Given the high prevalence of TI and limited literature detailing this condition, we conducted a retrospective review of cases of pediatric dermatophytosis presenting to the Faculty Group Practice of the Ronald O. Perelman Department of Dermatology, New York University School of Medicine (New York, New York), between 2005 and 2016. Among microbiologically confirmed dermatophytosis cases, we found that even with prior treatment, TI often presented with classic features of tinea such as annularity and scale. The majority of cases were treated with oral antifungals, though some were treated with topical antifungals alone. This case series underscores the need to maintain a high clinical suspicion for TI.

Keratosis pilaris is a common skin disorder comprising less common variants and rare subtypes, including keratosis pilaris rubra, erythromelanosis follicularis faciei et colli, and the spectrum of keratosis pilaris atrophicans. Data, and critical analysis of existing data, are lacking, so the etiologies, pathogeneses, disease associations, and treatments of these clinical entities are poorly understood. The present article aims to fill this knowledge gap by reviewing literature in the PubMed, EMBASE, and CINAHL databases and providing a comprehensive, analytical summary of the clinical characteristics and pathophysiology of keratosis pilaris and its subtypes through the lens of disease associations, genetics, and pharmacologic etiologies. Histopathologic, genomic, and epidemiologic evidence points to keratosis pilaris as a primary disorder of the pilosebaceous unit as a result of inherited mutations or acquired disruptions in various biomolecular pathways. Recent data highlight aberrant Ras signaling as an important contributor to the pathophysiology of keratosis pilaris and its subtypes. We also evaluate data on treatments for keratosis pilaris and its subtypes, including topical, systemic, and energy-based therapies. The effectiveness of various types of lasers in treating keratosis pilaris and its subtypes deserves wider recognition.

BACKGROUND:Little is known about how dermatologists prescribe hormonal antiandrogen acne treatment (HAAT). OBJECTIVE:The aim of this study was to investigate dermatologists' HAAT-prescribing habits and HAAT's impact on systemic antibiotic use in women with acne. METHODS:We performed a retrospective study at an academic medical center of female patients receiving HAAT (combined oral contraceptive [COC], spironolactone) for acne from January 2005 to October 2015. Data from a control group of female acne patients who never received HAAT were also collected. RESULTS:A total of 672 female patients received HAAT. Out of all systemic medications for acne, antibiotics were used as first-line treatment in 39% of patients, COCs in 12%, and spironolactone in 21%. Mean antibiotic durations in patients who initiated HAAT for the first time at the study site (250.4 days) were significantly longer than in patients who received HAAT prior to presentation and continued HAAT at the study site (192.0 days) (p = 0.021). A statistically significant inverse association was found between HAAT use and mean antibiotic duration (p = 0.016). CONCLUSIONS:HAAT is not typically used as a first-line systemic therapy in women with acne. HAAT usage is associated with shorter cumulative antibiotic durations and early HAAT initiation can decrease systemic antibiotic use in acne treatment.

PURPOSE/OBJECTIVE:Washing and over-the-counter cleansers are common interventions in acne vulgaris (AV), but the clinical evidence for their benefit is poorly understood. This systematic review presents clinical studies of washing and cleanser efficacy in acne vulgaris to guide treatment recommendations of dermatologists. MATERIALS AND METHODS/METHODS:We surveyed English-language articles indexed in MEDLINE (1951-March 2017) and EMBASE (1974-March 2017). Articles were required to be prospective studies of a single over-the-counter cleanser or washing intervention in AV with an objective AV outcome measurement published in a peer-reviewed journal. RESULTS AND CONCLUSIONS/CONCLUSIONS:Fourteen prospective studies representing 671 participants were included in this review. Modalities investigated included face washing frequency, true soap/syndet cleansing bars, antiseptic cleansers, alpha and beta-hydroxy (i.e. salicylic) acid cleansers, and several proprietary formulations. Given the low number of well-performed clinical studies of cleansers and washing, it is difficult to formulate reliable recommendations. We hope that our findings highlight the necessity of further investigation in this area.

Interfollicular epidermal melanocytes are continually subjected to environmental challenges and activate protective stress responses for survival. Dysregulation of these responses may increase susceptibility to autoimmune-mediated destruction resulting in progressive skin depigmentation typical of vitiligo. We have shown that challenging melanocytes from normally pigmented individuals (NMs) with chemicals known to trigger vitiligo, such as monobenzone, results in activation of the unfolded protein response (UPR). In this study, we investigated the impact of the PERK-eIF2alpha (activated PERK phosphorylates eIF2alpha) and IRE1alpha-XBP1 (activated IRE1alpha promotes splicing and expression of XBP1) axes of the UPR on melanocyte viability and sensitivity to monobenzone. NMs exhibited high basal PERK-eIF2alpha signaling compared to keratinocytes and dermal fibroblasts, and PERK knockdown substantially reduced melanocyte viability (p < 0.01), even in the absence of challenge. PERK inhibition increased sensitivity to monobenzone, while inhibition of IRE1alpha kinase activity, did not affect melanocyte toxicity. NMs that survive PERK knockdown were used to establish long-term cultures (shPERKLT), which exhibited a paradoxical increase in phospho-eIF2alpha with reduced sensitivity to monobenzone. Sustained eIF2alpha phosphorylation was reduced with downregulation of PKR and GCN2, alternative eIF2alpha kinases, suggesting a role for these kinases in melanocyte adaptation. Melanocytes from individuals with idiopathic vitiligo (VMs) exhibited increased sensitivity to monobenzone compared to NMs. VMs markedly activated the IRE1alpha/XBP1 pathway, reflected by an increase in XBP1 splicing. VMs also did not phosphorylate eIF2alpha in response to monobenzone treatment. Dysfunction of this protective response in VMs, in combination with increased IRE1alpha/XBP1 activity which promotes expression of chemokines, such as interleukin 6, that recruit immune cells to the skin, may contribute to the onset of autoimmunity in vitiligo. The UPR may thus represent a novel therapeutic target for vitiligo

The mechanisms that initiate vitiligo are poorly understood. Vitiligo triggers, such as monobenzone (MB) exposure, induce stress. Understanding the survival responses that combat this stress is key to determining why melanocytes become immune targets. MB induces oxidative and endoplasmic reticulum (ER) stress, which activates the unfolded protein response (UPR). PERK, a UPR initiator, phosphorylates eIF2alpha and master antioxidant regulator, NRF2. Here, we investigated the impact of PERK-eIF2alpha/-NRF2 activation on sensitivity to MB. Basal phospho-eIF2alpha and NRF2 levels are higher in melanocytes compared to fibroblasts or keratinocytes. PERK downregulation significantly reduced melanocyte viability (implicated in several autoimmune disorders) may link exposure to vitiligoinducing triggers with onset of autoimmunity