Unilateral Beau's Lines Associated with a Fingertip Crushing Injury

In 2005, a case was reported of a 36-year-old man who developed unilateral Beau's lines on all five fingernails of one hand following a crushing injury to his thumb. Beau's lines are transverse ridgings of the nail that indicate a temporary halt in nail matrix formation, typically associated with systemic diseases, trauma, drugs, or infection. While Beau's lines usually appear only on the affected finger, in this case, they appeared on all fingers of the injured hand, despite the absence of other injuries to the hand or wrist. This was an unusual presentation, as no previous reports in the English literature had described unilateral Beau's lines associated with a fingertip injury. The growth rate of the affected nails was normal, and the ridgings eventually disappeared as the nails grew. The exact cause of the Beau's lines in this case was unclear, but it was suggested that physiological changes from the injury, such as compromised blood supply or metabolism of the nail matrices, or immobilization of the hand, might have contributed to their formation.