Histologic features of nail cosmetics.

Nail cosmetics and adornments are widely used in today's society. However, their histologic features are not well characterized. Routine histologic examination and polarization of nail plate specimens in our academic dermatopathology practice at the Hospital of the University of Pennsylvania revealed 3 distinct histologic patterns of nail cosmetics: a hyperpigmented pattern with diffuse fine granular material, a layered pattern with a single linear band of polarizable material, and a hyperpigmented pattern with larger granules containing flecks of polarizable material. In our experience, submitting clinicians rarely indicate the patient's use of nail polish or other enhancements. Recognition of the histologic features of nail cosmetics is important to prevent confusion with dermatoses affecting the nail unit, and it will help dermatopathologists render more accurate diagnoses.