From the Research
Mees lines are white horizontal bands that appear on the fingernails or toenails, typically indicating systemic illness or poisoning, and are most commonly associated with arsenic poisoning, but can also occur with other heavy metal poisonings, severe infections, chemotherapy, heart attack, kidney failure, or other serious systemic conditions. These lines develop when nail growth is temporarily disrupted, causing abnormal keratinization that appears as transverse white lines across the nail plate 1. Unlike Beau's lines, which are depressions in the nail, Mees lines are not palpable and don't cause nail surface irregularities. They move outward as the nail grows, allowing clinicians to roughly estimate when the toxic exposure or illness occurred. Some key points to consider about Mees lines include:
- They can be caused by a variety of factors, including heavy metal poisoning, severe infections, and chemotherapy 2, 3, 4
- Treatment focuses on addressing the underlying condition or removing the source of poisoning rather than treating the nail changes themselves, as the lines will eventually grow out with the nail 5
- Medical evaluation is recommended to identify the underlying cause, which may require toxicology screening, especially if heavy metal poisoning is suspected
- Chelation therapy may be used to treat heavy metal poisoning, and has been shown to be effective in removing toxic metals from the body 2, 3, 4