Beau's lines secondary to acute illness in an elderly woman.

Dorsal plate growth from the proximal nail matrix can be affected by various acute systemic diseases (3). Although the exact mechanism for the genesis of Beau’s lines is unknown, it is considered that their presence reflects a temporary cessation of mitotic activity at the proximal nail matrix level due to a decrease in blood flow and metabolism (4). This may be caused by systemic and acute febrile diseases, renal failure, Stevens-Johnson syndrome, malnutrition, pemphigus, chemotherapeutic agents for cancer, or exposure to extreme cold in Raynaud’s disease patients (4-6).