Hardness of finger nails in well-nourished and malnourished populations

Abstract

1. The Knoop test of hardness applied to samples of finger nails from 334 healthy and 147 malnourished individuals showed statistically significant differences in the mean hardness of the nails of the two groups.2. The hardest nails were those of Filipino infants and children suffering from protein-energy deficiency. The softest nails were those of children in Guatemala recovering from protein-energy deficiency. Ranking of hardness appeared to be related to the severity and duration of protein-energy depletion.3. In children up to 12 years of age, hardness did not appear to be influenced by the age, sex, and racial origins of individuals or the environmental conditions to which nail specimens were exposed.4. Further studies are required to correlate hardness with clinical, biochemical and anthropometric measurements of nutritional status during protein-energy deprivation and during recovery. The causes of the differences in hardness need to be explored.