Onychomycosis: The Most Common Misdiagnosis in Nail Disease
Because onychomycosis is misdiagnosed so often, objective laboratory evidence is needed to confirm the diagnosis. Empirical antifungal treatment when no fungus is present can delay the correct diagnosis, allow disease to go untreated, and expose the patient to the cost and risk of adverse effects from unnecessary medication.3
Confirming the Diagnosis
Laboratory options commonly used for confirming a diagnosis of onychomycosis have advantages and disadvantages (Table 1).4-8 The combination of potassium hydroxide (KOH) and culture is the current standard for diagnosing onychomycosis.9 Extensive data support the use of nail clippings for pathology processing and periodic acid–Schiff (PAS) or Grocott-Gomori methenamine silver (GMS) staining that offers improved diagnostic accuracy. However, recent evidence suggests that polymerase chain reaction (PCR) is more sensitive, specific, and faster than either pathologic or culture-based methods.8
Participants should read the activity information, review the activity in its entirety, and complete the online post-test and evaluation. Upon completing this activity as designed and achieving a passing score on the post-test, you will be directed to a Web page that will allow you to receive your certificate of credit via e-mail or you may print it out at that time.
The online post-test and evaluation can be accessed at https://tinyurl.com/HDS19Supp.
Inquiries about continuing medical education (CME) accreditation may be directed to the University of Louisville Office of Continuing Medical Education & Professional Development (CME & PD) at [email protected] louisville.edu or 502-852-5329.
CME/CE Accreditation Statements
Physicians: This activity has been planned and implemented in accordance with the accreditation requirements and policies of the Accreditation Council for Continuing Medical Education (ACCME) through the joint providership of the University of Louisville School of Medicine and Global Academy for Medical Education, LLC. The University of Louisville School of Medicine is accredited by the ACCME to provide continuing education for physicians.
The University of Louisville School of Medicine designates this enduring activity for a maximum of 2.0 AMA PRA Category 1 Credits™. Physicians should only claim credit commensurate with the extent of their participation in the activity.
Joint Provider Accreditation Statement
In support of improving patient care, this activity has been planned and implemented by Postgraduate Institute for Medicine and Global Academy for Medical Education, LLC. Postgraduate Institute for Medicine is jointly accredited by the Accreditation Council for Continuing Medical Education (ACCME), the Accreditation Council for Pharmacy Education (ACPE), and the American Nurses Credentialing Center (ANCC) to provide continuing education for the health care team.
Continuing Nursing Education
The maximum number of hours awarded for this Continuing Nursing Education activity is 2.5 contact hours. Designated for 2.4 hours of pharmacotherapy credit for advanced practice nurses.
Dermatologists can benefit from education on recent developments in many areas of clinical practice. In psoriasis treatment, nearly all patients are prescribed topical therapies. New medications using improved vehicles and fixed-dose combinations have become available, and more are in development. New research linking psoriasis and risk of cardiovascular disease has provided a better understanding of the underlying pathological mechanism and the potential benefit of anti-inflammatory treatment. Recent epidemiologic data on atopic dermatitis in adults have important implications for diagnosis and treatment. In acne treatment, several efficacious systemic treatments are underutilized, and education on their risks and benefits may improve clinical practice. In the treatment of skin cancer, dermatologists should consider several systemic treatments in addition to surgery. Finally, a new botulinum toxin became available recently, and others are in development.
At the conclusion of this activity, participants should be better able to:
- Describe recent data on psoriasis treatment, including new vehicles for topical treatments, fixed-dose combination therapies, and investigational topical medications
- Review the relationship between psoriasis and cardiovascular disease (CVD) and the potential effects of psoriasis treatment on CVD risk
- Describe current research on the temporal patterns of atopic dermatitis onset and resolution and the differences in diagnosis and treatment approach for adult and pediatric patients
- Analyze the efficacy and safety of systemic therapies for acne
- Assess the current nonsurgical treatments for basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and localized melanoma
- Review the options for confirming the diagnosis and data on the use of topical and systemic treatments in the management of onychomycosis
- Assess the advantages and disadvantages of available botulinum toxins used to address patient concerns about facial aging
Individuals in a position to control the content of this educational activity are required to disclose: (1) the existence of any relevant financial relationship with any entity producing, marketing, re-selling, or distributing health care goods or services consumed by, or used on, patients with the exemption of nonprofit or government organizations and non–health-carerelated companies, within the past 12 months; and (2) the identification of a commercial product/device that is unlabeled for use or an investigational use of a product/device not yet approved.
Nathaniel J. Jellinek, MD, has indicated he has nothing to disclose.
Michael S. Kaminer, MD, has indicated he is a Consultant for Artic Fox, Cutera, Cytrellis, Endo, L’Oréal, Soliton, and Zeltiq.
Alan Menter, MD, has indicated he is on the Speakers Bureau for AbbVie, Celgene, Eli Lilly, Janssen, Novartis, and OrthoDoc.
Jonathan I. Silverberg, MD, PhD, MPH, has indicated he is on the Speakers Bureau for Regeneron/Sanofi; is a Consultant, and/or Advisory Board member for AbbVie, AnaptysBio, Asana, Dermavant, Eli Lilly, Galderma, GlaxoSmithKline, Glenmark, Kiniksa, LEO, Menlo, Pfizer, Realm, and Regeneron Sanofi; and has received Grant/Contracted Research Support from GlaxoSmithKline.
Linda F. Stein Gold, MD, has indicated she is on the Speakers Bureau for Galderma, LEO, Mayne, Pfizer, Sanofi/Regeneron, Taro, and Valeant; is a Consultant for Foamix, Galderma, LEO, Mayne, Menlo, Pfizer, Sanofi/ Regeneron, Sol-Gel, Taro, and Valeant; and has received Grant/Contracted Research Support from Foamix, Janssen, LEO, Menlo, Pfizer, and Valeant.
Christopher B. Zachary, MBBS, FRCP, has indicated he is a Consultant for Allergan, Candela, Sciton, and Solta.
University of Louisville CME & PD Advisory Board and Staff Disclosures: The University of Louisville CME & PD Advisory Board and office staff have nothing to disclose, with the following Board Member exceptions: Sathya Krishnasamy, MD – Novo Nordisk (Grant Funding); Ashlee Bergin, MD – Merck Pharmaceuticals (Speaking); Michael Sowell, MD – Amgen (Speaking) and Impax Pharmaceuticals (Grant Funding); Rainer Lenhardt, MD – CSL Behring, Mallinckrodt, and Merck (Speaking).
CME/CE Reviewers: Courtney R. Schadt, MD, Assistant Professor of Medicine, Chief of Dermatology, University of Louisville School of Medicine, Louisville, Kentucky, has nothing to disclose.
Postgraduate Institute of Medicine planners and managers have nothing to disclose.
Global Academy for Medical Education Staff: Shirley V. Jones, MBA; Eileen A. McCaffrey, MA; and Margaret McLaughlin, PhD, have nothing to disclose.
Off-Label/Investigational Use Disclosure
This CME/CE activity discusses the off-label use of certain approved medications as well as data from clinical trials on investigational agents. Such material is identified within the text of the articles.
- Gupta AK, Jain HC, Lynde CW, Macdonald P, Cooper EA, Summerbell RC. Prevalence and epidemiology of onychomycosis in patients visiting physicians’ offices: a multicenter Canadian survey of 15,000 patients. J Am Acad Dermatol. 2000;43(2 pt 1):244-248.
- Arrese JE, Piérard-Franchimont C, Piérard GE. Facing up to the diagnostic uncertainty and management of onychomycoses. Int J Dermatol. 1999;38(suppl 2):1-6.
- Gupta AK, Versteeg SG, Shear NH. Confirmatory testing prior to initiating onychomycosis therapy is cost-effective. J Cutan Med Surg. 2018;22(2):129-141.
- Gupta AK, Versteeg SG, Shear NH. Onychomycosis in the 21st century: an update on diagnosis, epidemiology, and treatment. J Cutan Med Surg. 2017;21(6):525-539.
- Wilsmann-Theis D, Sareika F, Bieber T, Schmid-Wendtner MH, Wenzel J. New reasons for histopathological nail-clipping examination in the diagnosis of onychomycosis. J Eur Acad Dermatol Venereol. 2011;25(2):235-237.
- Lilly KK, Koshnick RL, Grill JP, Khalil ZM, Nelson DB, Warshaw EM. Cost-effectiveness ofdiagnostic tests for toenail onychomycosis: a repeated-measure, single-blinded, cross-sectional evaluation of 7 diagnostic tests. J Am Acad Dermatol. 2006;55(4):620-626.
- Weinberg JM, Koestenblatt EK, Tutrone WD, Tishler HR, Najarian L. Comparison of diagnostic methods in the evaluation of onychomycosis. J Am Acad Dermatol. 2003;49(2):193-197.
- Gupta AK, Zaman M, Singh J. Fast and sensitive detection of Trichophyton rubrum DNA from the nail samples of patients with onychomycosis by a double-round polymerase chain reaction-based assay. Br J Dermatol. 2007;157(4):698-703.
- Gupta AK, Nakrieko KA. Onychomycosis infections: do polymerase chain reaction and culture reports agree? J Am Podiatr Med Assoc. 2017;107(4):280-286.
- Gupta AK, Gupta G, Jain HC, et al. The prevalence of unsuspected onychomycosis and its causative organisms in a multicentre Canadian sample of 30 000 patients visiting physicians’ offices. J Eur Acad Dermatol Venereol. 2016;30(9):1567-1572.
- Wlodek C, Trickey A, de Berker D, Johnson E. Trends in pediatric laboratory-diagnosed onychomycosis between 2006 and 2014 in the southwest of England. Pediatr Dermatol. 2016;33(6):e358-e359.
- Totri CR, Feldstein S, Admani S, Friedlander SF, Eichenfield LF. Epidemiologic analysis of onychomycosis in the San Diego pediatric population. Pediatr Dermatol. 2017;34(1):46-49.
- Tosti A, Piraccini BM, Lorenzi S. Onychomycosis caused by nondermatophytic molds: clinical features and response to treatment of 59 cases. J Am Acad Dermatol. 2000;42(2 pt 1):217-224.
- Gupta AK, Drummond-Main C, Cooper EA, Brintnell W, Piraccini BM, Tosti A. Systematic review of nondermatophyte mold onychomycosis: diagnosis, clinical types, epidemiology, and treatment. J Am Acad Dermatol. 2012;66(3):494-502.
- Shemer A, Davidovici B, Grunwald MH, Trau H, Amichai B. New criteria for the laboratory diagnosis of nondermatophyte moulds in onychomycosis. Br J Dermatol. 2009;160(1):37-39.
- Carney C, Tosti A, Daniel R, et al. A new classification system for grading the severity of onychomycosis: Onychomycosis Severity Index. Arch Dermatol. 2011;147(11):1277-1282.
- Lamasil [package insert]. East Hanover, NJ: Novartis Pharmaceuticals Corp; 2017.
- Sporanox [package insert]. Titusville, NJ: Janssen Pharmaceuticals, Inc; 2018.
- Gupta AK, Lynch LE, Kogan N, Cooper EA. The use of an intermittent terbinafine regimen for the treatment of dermatophyte toenail onychomycosis. J Eur Acad Dermatol Venereol. 2009;23(3):256-262.
- Elewski BE, Rich P, Pollak R, et al. Efinaconazole 10% solution in the treatment of toenail onychomycosis: two phase III multicenter, randomized, double-blind studies. J Am Acad Dermatol. 2013;68(4):600-608.
- Elewski BE, Aly R, Baldwin SL, et al. Efficacy and safety of tavaborole topical solution, 5%, a novel boron-based antifungal agent, for the treatment of toenail onychomycosis: results from 2 randomized phase-III studies. J Am Acad Dermatol. 2015;73(1):62-69.
- Tupaki-Sreepurna A, Jishnu BT, Thanneru V, et al. An assessment of in vitro antifungal activities of efinaconazole and itraconazole against common non-dermatophyte fungi causing onychomycosis. J Fungi (Basel). 2017;3(2). lc: doi 10.3390/jof3020020.
- Jo Siu WJ, Tatsumi Y, Senda H, et al. Comparison of in vitro antifungal activities of efinaconazole and currently available antifungal agents against a variety of pathogenic fungi associated with onychomycosis. Antimicrob Agents Chemother. 2013;57(4):1610-1616.
Nathaniel J. Jellinek, MD, has indicated he has nothing to disclose.