Beau’s Lines 5 April 2021 A nail condition that occurs after some systemic illness or trauma. They are horizontal depressions, usually across all nails, growing out from the matrix where the keratinisation process has been disturbed. Related Articles: Nail Plate Calcium Deficiency: What White Spots Really MeanGlossary: Systemic IllnessGlossary: FeverGlossary: ChemotherapyGlossary: High Fever