Other causative pathogens include Candida and nondermatophytic molds, in particular members of the mold genus Scytalidium (name recently changed to Neoscytalidium), Scopulariopsis, and Aspergillus. Candida species mainly cause fingernail onychomycosis in people whose hands are often submerged in water. Scytalidium mainly affects people in the tropics, though it persists if they later move to areas of temperate climate.
If the diagnosis is uncertain, direct microscopy of a potassium hydroxide preparation of a skin scraping (known as a KOH test) can confirm the diagnosis of athlete's foot and help rule out other possible causes, such as candidiasis, pitted keratolysis, erythrasma, contact dermatitis, eczema, or psoriasis. Dermatophytes known to cause athlete's foot will demonstrate multiple septate branching hyphae on microscopy.
There are many possible causes of foot rashes. Additional causes include irritant or contact dermatitis, allergic rashes from shoes or other creams, pompholyx (dyshidrotic eczema), psoriasis, yeast infections, and bacterial infections (gram negative toe web infection and erythrasma). Since these conditions are often indistinguishable on superficial visual examination, it is important for your doctor to do his best to identify the precise cause. Since fungal infections are potentially curable, it is important not to miss this diagnosis.
Modern treatments made surgery a last resort. “Before we had these 21st century medications, we didn’t have a good choice in how to deal with toenail fungus,” said Dr. Hinkes. “Oftentimes patients would come in, and out of frustration and lack of any real significant clinical cure with medication, they would ask for their nails to be permanently removed.”
Topical treatment is also usually recommended for children. One reason for this is that most oral medications aren’t suitable for children. Another reason is that children have thinner nails that grow more quickly, so it’s assumed that treatment with nail polish or creams is more likely to work in children than in adults. White superficial onychomycosis is also often treated with a nail polish or cream.