Nails whose distal plate splits into layers, with irregular, frayed, and torn borders—almost resembling
the scaling of dry skin. Present in 20% of adults (and even more in older subjects), brittle nails may be
hereditary or simply aging-related. They also may be due to strong solvents or repeated immersion in water
(e.g., dishwashers). Dysmetabolic states (such as hyperthyroidism, malnutrition, and iron or calcium
deficiency) must always be ruled out
the scaling of dry skin. Present in 20% of adults (and even more in older subjects), brittle nails may be
hereditary or simply aging-related. They also may be due to strong solvents or repeated immersion in water
(e.g., dishwashers). Dysmetabolic states (such as hyperthyroidism, malnutrition, and iron or calcium
deficiency) must always be ruled out