How useful is periodic acid-Schiff stain to detect fungi in biopsies from dermatoses of the palms and soles?

There is a low concordance rate between the clinical suspicion and the actual demonstration of fungi by PAS stain in dermatoses of the palms and soles. Routine PAS stains in non-suspected cases have a relatively low yield, which may be improved by limiting the PAS stain to reaction patterns not readily classified as particular diagnostic entities.