[Brittle nails. Objective assessment and therapy follow-up].

The different methods that are available for the assessment and quantification of "brittle nails" and for the evaluation of various therapeutical approaches are compared. At this time, measurement of the swelling properties is the best documented and most reliable method for studying the treatment of brittle nails. Reliable qualitative data can also be obtained by scanning electron microscopy. Measurement of the transonychial water loss and assessment of thickness and density of nails by ultrasound have also been used successfully, but the methodology still has to be improved and the reproducibility, confirmed.