%0 Journal Article %T New Concepts in Median Nail Dystrophy, Onychomycosis, and Hand, Foot, and Mouth Disease Nail Pathology %A Nathan Y. Hoy %A Alexander K. C. Leung %A Andrei I. Metelitsa %A Stewart Adams %J ISRN Dermatology %D 2012 %R 10.5402/2012/680163 %X Nails are underutilized as diagnostic tools, despite being involved in many dermatologic conditions. This paper explores new concepts in the treatment of median nail dystrophy (MND), onychomycosis, and the nail pathology of hand, foot, and mouth disease (HFMD). A Pubmed database literature search was conducted for MND treatment, onychomycosis treatment, and HFMD nail pathology. Only papers published after January 2008 were reviewed. The results showed that 0.1% tacrolimus ointment can be an effective treatment for MND. Early studies on laser therapy indicate that it is a safe and efficacious treatment option for onychomycosis, compared to conventional oral antifungal agents. Vicks VapoRub (The Proctor & Gamble Company, Cincinnati, OH) is effective against onychomycosis and is a reasonable option in patients who choose to forgo conventional treatments. Lastly, there is evidence to support a correlation between HFMD and onychomadesis. 1. Introduction Nails are often underutilized as a diagnostic tool in dermatology, despite being involved in a wide variety of dermatologic conditions. New ideas in pathophysiology, advances in diagnostic and management techniques, and innovations in treatment are continuously evolving in the field of nail disease. In this paper, we aim to shed light on some of these fascinating developments with respect to the treatment of median nail dystrophy (MND), onychomycosis, and the nail pathology of hand, foot, and mouth disease (HFMD). At a basic level, the nail unit is composed of a matrix on a bed, surrounded by skin. The distal nail matrix is called the lunula, which is the half-moon shape at the base of the nail, and is responsible for the production of the ventral nail plate. Melanocytes are also contained within the nail matrix and are usually quiescent but may become active and impart pigmentation to the keratinocytes in the nail plate. The nail plate overlies the nail bed, which contains blood vessels and nerves. Skin surrounding the nail plate composes the perionychium, which can be further divided into proximal and lateral nail folds and the hyponychium, the area beneath the free edge of the nail [1]. Production of the nail plate is continuous from embryonic development until death. The mean growth rate of fingernails and toenails per month is 3£żmm and 1£żmm, respectively, implying approximately 4¨C6 months to completely regenerate a fingernail or 8¨C12 months to replace a toenail. Nail growth is linked to a number of factors, such as age, presence of systemic and localized diseases, and medications [1, 2]. 2. Methods Using %U http://www.hindawi.com/journals/isrn.dermatology/2012/680163/