Transverse ridges or grooved white lines across the fingernails (or toenails), as seen following a severe febrile disease, malnutrition, trauma, myocardial infarction, thyroid dysfunction, trauma, coronary occlusion, etc.
Beau's lines are transverse depressions on the fingernails or toenails. The line is deep and grooved that run from side to side on the nail. Nails with Beau's lines thus appear to have ridged nail plate. French physician Joseph H.S. Beau was the first to describe this condition in relation to a systemic event. Beau's lines appear on the nails often after a severe febrile disease, malnutrition, trauma, myocardial infarction, thyroid dysfunction, trauma, coronary occlusion, chemotherapy, etc. It is believed that these diseases affecting the entire body could have affected the growth plate of the nail. Thus, this condition may be caused by a temporary cessation of cell division in the nail matrix as an effect of a disease, malnutrition, chemotherapy, etc. There are also instances wherein only one nail is affected and its formation is often associated with local rather than systemic trauma. Beau's lines though are harmless and the lines will grow out eventually. Thus, there are no particular treatment for this condition, except for keeping oneself healthy particularly when the cause is poor nutrition.
Word origin: named after French physician, Joseph H.S. Beau, who first described it