Variability in Systemic Treatment Efficacy for Onychomycosis: Information That Clinical Studies Do Not Impart to the Office Dermatologist.

Wide differences in the cure rates of onychomycosis in various clinical studies can be avoided if we bear in mind some insights that will help us make study results more consistent. We suggest less rigid criteria in defining the cure rate, the inclusion of all toenails in studies, and the exclusion of nails with a history of trauma. Rather than address patients as a homogenous group, regardless of age, we suggest dividing them into age groups. Researchers should not forget inflammatory diseases that can imply changes on the nails and should take into account the duration of onychomycosis, nail changes caused by asymmetry, and the possibility of dermatophytoma.