Onychomycosis: Diagnosis and definition of cure Richard K. Scher, MD, FACP, a Amir Tavakkol, PhD, Dip Bact, b Ba ´rdur Sigurgeirsson, MD, PhD, c Roderick J. Hay, DM, d Warren S. Joseph, DPM, e Antonella Tosti, MD, f Philip Fleckman, MD, g Mahmoud Ghannoum, MSc, PhD, h David G. Armstrong, DPM, i Bryan C. Markinson, DPM, j and Boni E. Elewski, MD k New York, New York; East Hanover, New Jersey; Reykjavik, Iceland; Belfast, Ireland; Coatesville, Pennsylvania; Bologna, Italy; Seattle, Washington; Cleveland, Ohio; North Chicago, Illinois; and Birmingham, Alabama Until now, there has been no agreement on criteria defining resolution of onychomycosis. Most published reports use clinical and mycological cure, which comprises a completely normal-appearing nail plate, and negative nail culture and microscopy results, as the end point for defining success of therapeutic intervention. Reported here is the definition of onychomycosis, which delineates both primary and secondary criteria for diagnosis of onychomycosis and identifies clinical and laboratory parameters to define a resolved fungal nail infection. Onychomycosis cure is defined by the absence of clinical signs or the presence of negative nail culture and/or microscopy results with one or more of the following minor clinical signs: (1) minimal distal subungual hyperkeratosis; and (2) nail-plate thickening. Clinical signs indicative of persistent onychomycosis at the end of the observation period include (1) white/yellow or orange/brown streaks or patches in or beneath the nail plate; and (2) lateral onycholysis with subungual debris. Although nail appearance will usually continue to improve after cessation of therapy, the nails may have a persistent abnormal appearance even in cases where treatment has been effective. ( J Am Acad Dermatol 2007;56:939-44.) O nychomycosis is estimated to affect ap- proximately 2% to 13% of the population of North America and Europe. 1-7 Both physician and patient expectations of treatment outcome are influenced by the widely varying per- ceptions of what constitutes cure of onychomycosis. Yet, physicians often do not discuss with their patients the likely end result of therapy. From the Department of Dermatology, Columbia University, New York a ; Dermatology Clinical Research, Novartis Pharmaceuticals Corporation, East Hanover b ; Department of Dermatology, Uni- versity of Iceland, Reykjavik c ; Queens University Belfast d ; Ve- terans Administration Medical Center, Coatesville e ; Department of Dermatology, University of Bologna f ; Department of Medi- cine (Dermatology), University of Washington School of Med- icine, Seattle g ; Department of Dermatology, Case Western Reserve University, Cleveland h ; Dr William M. Scholl College of Podiatric Medicine at Rosalind Franklin University of Medi- cine and Science, Green Oaks, North Chicago i ; Department of Orthopedic Surgery, Mount Sinai Medical Center, New York j ; and Department of Dermatology, University of Alabama, Birmingham. k Supported by Novartis Pharmaceuticals Corporation. Disclosure: This report is based on a consensus conference sponsored by Novartis Pharmaceuticals Corporation. Technical assistance from CPE Communications is appreciated. All con- tributors have received honoraria from Novartis Pharmaceuti- cals Corporation for their participation in the consensus conference meeting that formed the basis for this article. Dr Tavakkol is Director of Dermatology Clinical Research at Novartis Pharmaceuticals Corporation. All authors received honoraria from Novartis and are consultants/advisors, speakers, and investigators for Novartis. Dr Scher is a consultant, and investigator, and received honoraria and grants from Barrier. He is also an advisory board member, consultant, and received honoraria from Stiefel. Dr Sigurgeirsson is an investigator, consultant, and speaker for Galderma and has received grants, honoraria, and salary from this company. He is also an advisory board member, investigator, and consultant for Stiefel and has received grants and honoraria from this company. Dr Hay is an advisory board member receiving honoraria from Barrier. Dr Tosti is an advisory board member receiving honoraria from both Stiefel and Galderma. Dr Ghannoum is an investigator and speaker receiving grants and honoraria from Pfizer; and investigator and speaker receiving grants and honoraria from Enzon; an investigator and consultant receiving grants and honoraria from Schering-Plough; and investigator and speaker receiving grants and honoraria from Merck; an inves- tigator receiving grants and honoraria from Vicuron; and a consultant receiving honoraria from NexMed. Dr Armstrong is an advisory board member and investigator for Lilly. He is also an advisory board member of, investigator for, and receives honoraria from Pfizer. Dr Markinson is a speaker, consultant, and advisory board member receiving honoraria and stock options for Bradley Pharmaceuticals and is an advisory board member receiving honoraria from Stiefel. Dr Elewski is an advisory board member receiving honoraria from Anacor and Stiefel and an investigator for Barrier and Novartis. Accepted for publication December 21, 2006. Reprint requests: Boni E. Elewski, MD, Department of Dermatology, University of Alabama, 700 18 St S, Suite 414, Birmingham, AL 35233. E-mail: beelewski@aol.com. Published online February 20, 2007. 0190-9622/$32.00 ª 2007 by the American Academy of Dermatology, Inc. doi:10.1016/j.jaad.2006.12.019 939