What is onychomalacia it an infection of the nails?

Onychomalacia is not an infection of the nails. It's a condition in which the nails become soft and brittle. It is often caused by chronic exposure to water or other chemicals, such as those found in nail polish remover. Onychomalacia can also be caused by a nutritional deficiency, such as vitamin B12 or iron deficiency, or by a medical condition, such as thyroid disease or psoriasis.