Beau’s Lines
Definition:Beau’s lines are deep transverse grooves on the surface of the nails. The groove demarcates a difference in the appearance of the nail. In practice, Beau’s lines are a common observation and a sign of non-specific disease processes.

Causes:

Beau’s lines may appear several weeks or months following a protracted systemic illness, high fever, infections, following chemotherapy, coronary occlusion, hypocalcaemia, skin disease, in diabetics and with psoriasis. They may also develop as a consequence of medications, immunosuppressants, severe malnutrition and from trauma.

Examination:

The depth of the line may provide an indication to the severity of the illness. The width of the groove may potentially relate to the duration of the illness that has affected the nail.  Also one can make an estimation based on the following consideration; the nails grow by approx. 1 mm, every six to 10 days. Thus the timing of the disease development may also be estimated by measuring the distance from the transverse line to the nail bed.