Investigation of prevalence of onychomycosis due to yeast fungi in dystrophic nails of patients who referred to Razi hospital (2010 - 2011)

Yeasts are one of the most common causes of onychomycosis. In countries like Iran, Saudi Arabia, Italia and Spain, yeasts are reported as the most frequent causes of onychomycosis. Inhibition of the immune system such as chemotherapy, radiation therapy, the use of broad spectrum antibodies, aggressive treatment with corticosteroids, HIV and diabetes melitus predispose the body with these fungal infections. Onychomycosis due to yeast has a higher prevalence in finger nails and its incidence in women is two or three times more than men. In some occupations such as nurses, dish washers, confectionery and housewives it can be more observed. Among the yeasts, Candida albicans is the most common agent onychomycosis. This study has been designed for investigation of prevalence of onychomycosis due to yeast in patients who referred to Razi hospital.

This was a cross sectional study and 700 dystrophic nail samples were examined by both direct examination and culturing. In direct examination KOH (hydroxide potassium) 20% and for culturing saboroud dexterose agar (S) media were used. For identification yeasts complementary examination were done such as: Reynold braude test, API test and culturing on candida chrom agar media and corn meal agar media were used. For investigation of relevance between variables, Chi-square test and Fisher exact test were used.

Of 700 dystrophic nail samples (15.71%), 110 samples were yeast positive by both direct examination and culturing. Thirty one patients were males and 79 patients were females and in both sexes those most infected were between 50-59 years of age (27.3%). Eighty patients had fungal infection of finger nails and 16 patients had fungal infection on toe nails; 14 patients had both infections on finger and toe nails. The most frequent detected yeast species was Candida albicans (42.7%) which was followed by Candida parapsilosis (20.9%), Candida tropicalis (14.5%), Candida krusei (12.7%), Candida glabrata (3.6)%, Candida gillermondi (2.7%), and Candida lousitani, famatata, rodotroula (each 0.9%). The most common clinical type noted was distal subungual onychomycosis in 50% of cases. In this study 52 patients (48.1%) had diabetes which was the most common disease between patients with onychomycosis due to yeasts.

Diagnosis of onychomycosis due to yeast is very important because it shows the person’s immune response. Identification of pathogenic yeast species in terms of epidemiology and selecting appropriate and effective treatment is important.