John Koo

University of California, San Francisco, San Francisco, California, United States

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Publications (94)228.32 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Phototherapy is an effective treatment for several inflammatory skin conditions. While its utility is well-recognized (e.g. 45% of American Academy of Dermatology members prefer phototherapy as a first-line psoriasis treatment) [1] its use has significantly declined in the U.S. [2, 3] Part of the problem may be the training of residents. A survey conducted in 1994, which included 66 dermatology chief residents, found that over 50% of respondents received fewer than 3 hours of phototherapy training annually, and 55% reported no hands-on tutorials. [4] Many residents felt ill-prepared to provide phototherapy. Based on a similar study surveying dermatology residents, our results indicate that 20 years later, phototherapy training remains lacking. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Photodermatology Photoimmunology and Photomedicine 05/2015; DOI:10.1111/phpp.12182 · 1.30 Impact Factor
  • Eric Sorenson, John Koo
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    ABSTRACT: Biologic agents have greatly enhanced the treatment of moderate-to-severe plaque psoriasis. Previous reviews of the safety of biologic agents have included patients with conditions other than psoriasis and/or have not used statistical significance as the primary analytic focus. Our aim was to review the current literature to identify significantly increased adverse events associated with the use of etanercept, adlimumab and ustekinumab for the treatment of moderate-to-severe plaque psoriasis. We performed a search of Ovid MEDLINE and the Cochrane Library to identify clinical trials, open-label extension studies and meta-analyses reporting statistical analysis of adverse events associated with the use of etanercept, adlimumab and ustekinumab for the treatment of moderate-to-severe plaque psoriasis. We identified 17 clinical trials, 2 open-label extension studies and 8 meta-analyses. Adverse events reported to be significantly increased included squamous cell carcinoma (SCC), injection-site reaction, and headache associated with etanercept, overall nonmelanoma skin cancer (NMSC), SCC, and upper respiratory tract infection associated with adalimumab, and no significantly increased adverse events associated with ustekinumab. Current evidence suggests that when analyzed among patients with plaque psoriasis, few adverse effects of the biologic agents etanercept, adalimumab and ustekinumab have reached statistical significance. Further long-term studies conducting analysis of statistical significance should be performed.
    Journal of Dermatological Treatment 04/2015; DOI:10.3109/09546634.2015.1027167 · 1.76 Impact Factor
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    ABSTRACT: Psoriasis is a chronic immune disorder that affects 2-3% of the US population. Ustekinumab, a monoclonal antibody against IL-23/12, has shown great efficacy in treating psoriasis. Here we present a rare finding of a patient with plaque-type psoriasis who was diagnosed with congestive heart failure after initiating treatment with ustekinumab. The patient experienced full recovery of cardiac function upon discontinuation of ustekinumab.
    04/2015; DOI:10.1016/j.jdds.2015.03.003
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    ABSTRACT: Chronic graft-vs-host disease (GVHD) affects 50% to 70% of patients who receive allogeneic hematopoietic cell transplants (HCTs), and the skin is the most common site of involvement. Chronic cutaneous GVHD can present with sclerotic or nonsclerotic changes of the skin and often requires treatment with systemic immunosuppressants, extracorporeal photopheresis, or phototherapy. We describe the first reported case, to our knowledge, of the effective treatment of sclerotic chronic cutaneous GVHD with narrowband UV-B (NB UV-B) phototherapy. A woman in her 40s presented with sclerotic chronic GVHD of the skin 6 years after HCT for treatment of chronic myelogenous leukemia. The patient's cutaneous disease progressed despite treatment with prednisone and oral tacrolimus. The patient was initiated on NB UV-B phototherapy 3 times per week, resulting in clinically significant improvement of cutaneous lesions over the first 2 months. The NB UV-B regimen allowed for a reduction of prednisone dose and continued control of cutaneous GVHD over 6 months of therapy. Our case report describes the successful use of NB UV-B phototherapy for the treatment of sclerotic chronic cutaneous GVHD. Further study should be performed to evaluate the effectiveness of this therapeutic modality for patients with sclerotic chronic cutaneous GVHD.
    JAMA Dermatology 03/2015; DOI:10.1001/jamadermatol.2015.0175 · 4.30 Impact Factor
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    ABSTRACT: Patient satisfaction is an important component of dermatological care that reflects patients' perspectives on the care they receive. While physicians' expertise and judgment should always remain the foundation of providing appropriate and effective care, the patient experience can also be influenced by interpersonal relationships, expectations, and a sense of agency in the treatment patients receive. Dermatology providers can use practical techniques such as sitting rather than standing, reframing the concept of cure, and engaging patients in treatment decisions to improve the patient-provider experience and thereby optimize patient satisfaction.
    American Journal of Clinical Dermatology 01/2015; 16(1). DOI:10.1007/s40257-014-0111-7 · 2.52 Impact Factor
  • Journal of the American Academy of Dermatology 01/2015; 72(1):e40-2. DOI:10.1016/j.jaad.2014.09.050 · 5.00 Impact Factor
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    ABSTRACT: Patient satisfaction has been and is of growing importance in healthcare. Recent healthcare initiatives aim to provide physicians with performance feedback reports based partially on patient completed surveys; thus, patient satisfaction will be an even more important determinant of high quality care. In the field of dermatology, patient satisfaction is particularly relevant and at times difficult to achieve, since many patients are plagued with chronic skin diseases often requiring intensive topical regimens or undesirable systemic immunosuppressants. The discussion of patient satisfaction is usually restricted to encounters with the general clinic population leaving encounters with difficult patients largely underreported; therefore, we provide examples of more common difficult patient encounters a dermatologist may face with specific recommendations on how to best optimize patient satisfaction.
    Clinics in Dermatology 09/2014; DOI:10.1016/j.clindermatol.2014.01.001 · 1.93 Impact Factor
  • Eva Wang, John Koo, Elie Levy
    Journal of the American Academy of Dermatology 08/2014; 71(2):391–393. DOI:10.1016/j.jaad.2014.03.046 · 5.00 Impact Factor
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    ABSTRACT: Phototherapy is often used to treat inflammatory skin conditions such as psoriasis and eczema. Much progress has recently been made in understanding the mechanisms underlying the local, cutaneous immune effects induced by phototherapy. Unlike many immunosuppressive drugs used in the management of inflammatory skin disease, phototherapy not only targets effector immune cells but also appears to up-regulate regulatory T cells (Tregs). Additionally, phototherapy reverses epidermal barrier abnormalities common in these diseases, allowing for restoration of cutaneous homeostasis. J Drugs Dermatol. 2014;13(5):564-568.
    Journal of drugs in dermatology: JDD 05/2014; 13(5):564-8. · 1.32 Impact Factor
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    ABSTRACT: Patients with psoriasis have been shown to have a higher prevalence of other autoimmune diseases including celiac disease, a condition marked by sensitivity to dietary gluten. A number of studies suggest that psoriasis and celiac disease share common genetic and inflammatory pathways. Here we review the epidemiologic association between psoriasis and celiac disease and perform a meta-analysis to determine whether patients with psoriasis more frequently harbor serologic markers of celiac disease. We also examine whether a gluten-free diet can improve psoriatic skin disease.
    Journal of the American Academy of Dermatology 04/2014; 71(2). DOI:10.1016/j.jaad.2014.03.017 · 5.00 Impact Factor
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    ABSTRACT: Patients with psoriasis are increasingly turning to the use of alternative and complementary medicine to manage their psoriasis. Patients often inquire about what dietary supplements may be beneficial, including the use of oral vitamin D, vitamin B12, selenium, and omega-3 fatty acids in fish oils. In this review we examine the extent to which each of these common nutritional interventions has been studied for the treatment of psoriasis. We weighed evidence from both controlled and uncontrolled prospective trials. The evidence of benefit was highest for fish oils. For other supplements, there is need for additional large, randomized clinical trials to establish evidence of efficacy.
    Journal of the American Academy of Dermatology 04/2014; 71(3). DOI:10.1016/j.jaad.2014.03.016 · 5.00 Impact Factor
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    ABSTRACT: One of the most frequently asked questions by patients with psoriasis is whether dietary changes can improve their condition. Included in this discussion is whether dietary weight loss can benefit their skin disease. Obesity has been associated with a proinflammatory state and several studies have demonstrated a relationship between body mass index and psoriasis severity. However, the question of whether weight loss interventions can impact psoriasis outcome is less clear. Here, we review the literature to examine the efficacy of weight loss interventions, both dietary and surgical, on psoriasis disease course.
    Journal of the American Academy of Dermatology 04/2014; 71(1). DOI:10.1016/j.jaad.2014.02.012 · 5.00 Impact Factor
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    ABSTRACT: The efficacy of biologic therapy in treating plaque-type psoriasis is well documented. However, there is less data for use in other psoriasis subtypes, such as erythrodermic and generalized pustular psoriasis. We sought to review the safety and efficacy of biologic medications in the treatment of these severe subtypes of psoriasis and to identify strategies to help clinicians optimally manage these patients. We searched Pubmed for English language literature that assessed the use of biologic medication to treat erythrodermic or generalized pustular psoriasis. The primary literature included cases reports, cases series, and open-label, uncontrolled trials. There were no head-to-head studies or other controlled trials. In both erythrodermic and generalized pustular psoriasis, infliximab was used to treat over half of the reported cases. Other biologic medications that were successfully used included etanercept, ustekinumab, adalimumab, and anakinra. Most cases reported improvement with biologic therapy. Serious adverse events were reported in 10-12% of the patients. Although the evidence is limited, biologic therapy appears to be effective in treating erythrodermic and generalized pustular psoriasis. In order to assess the comparative efficacy and safety of the biologic medications, larger controlled studies are needed. J Drugs Dermatol. 2014;13(3):342-354.
    Journal of drugs in dermatology: JDD 03/2014; 13(3):342-54. · 1.32 Impact Factor
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    ABSTRACT: Abstract Background: Studies investigating the molecular basis of psoriasis have established the central roles of TNFα, interleukin (IL)-12, IL-22 and IL-23 and there is increasing evidence that IL-17 plays a critical role in the complex pathophysiology. Preclinical studies suggest that IL-17 is a desirable therapeutic target for psoriasis treatment. Methods: We reviewed the results of the phase II clinical trials for the anti-IL-17 agents secukinumab, ixekizumab and brodalumab in order to assess the efficacy and safety profile of each agent. Results: By week 12, the proportion of patients reaching Psoriasis Area and Severity Index (PASI 75) was comparable among the most efficacious dosage between the different agents (secukinumab 82%, ixekizumab 83% and brodalumab 82%; p < 0.001 compared to placebo for all agents). The safety profiles of the agents were similar with the most frequently reported adverse events of nasopharyngitis, upper respiratory infections and injection site reaction. A small percentage of patients experienced low-grade neutropenia that was predominantly transient and asymptomatic. Conclusion: The anti-IL-17 agents demonstrated a rapid and robust clinical improvement accompanied by a favorable short-term safety profile. The results of the phase II trials support the theory that the IL-17 pathway is an essential target in psoriasis treatment.
    Journal of Dermatological Treatment 02/2014; 26(1). DOI:10.3109/09546634.2013.878448 · 1.76 Impact Factor
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    ABSTRACT: Abstract Background: Generalized UVB phototherapy has been established as an effective and safe treatment for chronic plaque-type psoriasis for decades and in recent years, targeted 308-nm excimer laser has emerged as an equally safe and more effective treatment option. While traditional dosimetry for laser has been determined either through minimal erythema dose (MED) or a combination of the patient's Fitzpatrick skin type and the level of plaque induration, we have developed "Plaque-based Sub-blistering Dosimtery" based on observations that administering anywhere from 8 to 16 multiples of MED to psoriatic plaques has resulted in clearance after one treatment with longer remission rates than the traditional dosing protocol. Case report: The authors describe a case in which a patient achieved PASI 75 following only two treatments with 308 nm excimer laser using this new protocol. Biopsies taken before and after treatment reveal a dramatic decrease in CD4 + T cells as well as TNF-alpha- and IL-2-producing T cells. Conclusion: This case demonstrates using a more aggressive dosing protocol determined by plaque testing is well-tolerated and can lead to excellent clearance with minimal side effects and comorbidity.
    Journal of Dermatological Treatment 02/2014; 26(1). DOI:10.3109/09546634.2013.879094 · 1.76 Impact Factor
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    ABSTRACT: Abstract Background: Psoriasis is a chronic skin condition traditionally believed to involve the Th1 pathway. Recently, the IL-23/Th17/IL-17 pathway has been highlighted in the pathogenesis of psoriasis and other autoimmune inflammatory conditions. From a clinician's perspective, we sought to review the basic science data relevant to IL-17's role in psoriasis pathogenesis. Methods: We performed a Pubmed and Web of Knowledge search for English articles starting from 1990 that discussed the Th17 pathway. Search terms such as "IL-17" and "psoriasis" were utilized. Results: The IL-17 pathway is regulated by IL-23, a cytokine that is vital for the expansion and maintenance of the Th17 cell population. Th17 derived cytokines (IL-17A, IL-17F, IL-17A/F and IL-22) were elevated in both psoriasis-like murine models and human psoriatic lesional biopsies. Ixekizumab (anti-IL-17A) treatment of psoriasis was found to normalize levels of IL-17 downstream gene products. Conclusion: Both preclinical and clinical studies support the central role of IL-17 in the pathogenesis of psoriasis.
    Journal of Dermatological Treatment 02/2014; 26(1). DOI:10.3109/09546634.2013.879093 · 1.76 Impact Factor
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    ABSTRACT: Regulatory T cells (Tregs), which are characterized by expression of the transcription factor Foxp3, are a dynamic and heterogeneous population of cells that control immune responses and prevent autoimmunity. We recently identified a subset of Tregs in murine skin with properties typical of memory cells and defined this population as memory Tregs (mTregs). Due to the importance of these cells in regulating tissue inflammation in mice, we analyzed this cell population in humans and found that almost all Tregs in normal skin had an activated memory phenotype. Compared with mTregs in peripheral blood, cutaneous mTregs had unique cell surface marker expression and cytokine production. In normal human skin, mTregs preferentially localized to hair follicles and were more abundant in skin with high hair density. Sequence comparison of TCRs from conventional memory T helper cells and mTregs isolated from skin revealed little homology between the two cell populations, suggesting that they recognize different antigens. Under steady-state conditions, mTregs were nonmigratory and relatively unresponsive; however, in inflamed skin from psoriasis patients, mTregs expanded, were highly proliferative, and produced low levels of IL-17. Taken together, these results identify a subset of Tregs that stably resides in human skin and suggest that these cells are qualitatively defective in inflammatory skin disease.
    The Journal of clinical investigation 02/2014; 124(3). DOI:10.1172/JCI72932 · 13.77 Impact Factor
  • 02/2014; 93(2):E1-2.
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    ABSTRACT: The raised, scaly, and erythematous plaques associated with psoriasis can be cosmetically disfiguring, which may provoke disgust, fear, and aversion in others. Consequently, the social stigma of psoriasis can be devastating for patients, evoking feelings of shame and anxiety about how they are perceived. In recent years, appreciation of psoriasis as a disease that can cause social distress and impairment has increased. This review discusses the manifold social burdens of psoriasis; different and emerging therapies that may mitigate these burdens by improving outcomes associated with the underlying disease; and psoriasis management in the context of healthcare reform changes focused on assessing the quality and value of patient care. The social impact of psoriasis is substantial (eg, affecting interpersonal relationships, sexual function, intimacy, occupational success). Undertreatment of psoriasis continues, despite evidence that biologic agents may lessen the physical and social burdens and provide greater patient satisfaction than conventional therapy. Changes in healthcare place an even greater emphasis on measurable outcomes, including patient satisfaction. Increased understanding of the social burden of psoriasis may lead to provision of more comprehensive, holistic care that is in concordance with the evolving restructured reimbursement system.
    Dermatology online journal 01/2014; 20(8).
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    ABSTRACT: Abstract Psoriasis is a chronic skin disorder that affects 1% to 3% of the general population worldwide. Streptococcal infection, especially streptococcal pharyngitis, has been shown to be a significant trigger of psoriasis in some patients, possibly by sensitizing T cells to keratin epitopes in the skin. Due to the role of the palatine tonsils as an immunological organ that may generate autoreactive T cells, tonsillectomy has been investigated as a treatment for psoriasis. Tonsillectomy originally gained acceptance in Japan as a treatment for palmoplantar pustulosis, a condition that shares features with pustular psoriasis. Subsequently, tonsillectomy has been used for the treatment of plaque psoriasis and guttate psoriasis. Recently, the first randomized, controlled clinical trial of tonsillectomy was performed. Here, we review the available evidence for the benefit of tonsillectomy as a treatment for palmoplantar pustulosis and psoriasis. We also discuss molecular studies aimed at understanding the role of tonsils in skin disease.
    Journal of Dermatological Treatment 11/2013; 25(6). DOI:10.3109/09546634.2013.848258 · 1.76 Impact Factor

Publication Stats

1k Citations
228.32 Total Impact Points


  • 1997–2015
    • University of California, San Francisco
      • Department of Dermatology
      San Francisco, California, United States
  • 2013
    • University of Texas at San Antonio
      San Antonio, Texas, United States
  • 2006–2013
    • University of Southern California
      • Keck School of Medicine
      Los Angeles, California, United States
  • 2012
    • University of San Francisco
      San Francisco, California, United States
    • The University of Arizona
      • College of Medicine
      Tucson, AZ, United States
  • 2011
    • University of Toronto
      • Department of Medicine
      Toronto, Ontario, Canada
    • University of Illinois at Chicago
      Chicago, Illinois, United States
  • 2010
    • University of Pittsburgh
      • Department of Dermatology
      Pittsburgh, Pennsylvania, United States
  • 2007
    • University of California, Irvine
      • Department of Pediatrics
      Irvine, CA, United States
  • 2005
    • California State University, Sacramento
      Sacramento, California, United States
  • 2004
    • CSU Mentor
      Long Beach, California, United States
  • 1999–2003
    • Mount Sinai School of Medicine
      • Department of Dermatology
      Manhattan, NY, United States