A Decreased Growth Rate of the Great Toe Nail Observed in Patients with Distal Subungual Onychomycosis

ABSTRACT

BACKGROUND: There are prerequisites for fungal nail infection fungal organism, susceptible host, and environments with damaged nail. OBJECTIVE: The purpose of this study was to evaluate the growth rate of the great toe nail in distal subungual onychomycosis(DSO). MATERIALS AND METHODS: The subjects are 60 adult patients with DSO and 19 age- and sex-matched controls with tinea pedis but no DSO. The growth rate of the great toe nail was measured. Data were evaluated with Mann-Whitney U-test and regression analysis using the statistical program for PC. RESULTS: The growth rate of the patients group showed a decrease against that of the controls. The equation for expected nail growth rate of specific age and sex was as follows the expected nail growth rate(mm/day) = 0.07382 + (0.01498 × G) - (0.00033 × Age) - (0.00669 × S) if a person has DSO, G is 1, and if he has no DSO, G is 2; if a person is male, S is 1, and, female, 2. CONCLUSION: Patients with DSO often have a decreased growth rate of the nail compared with that of the controls. The authors propose the equation of expected nail growth rate in persons with or without DSO, and think that the growth rate of the nail is one of factors in the pathogenesis of onychomycosis.