| Koilonychia | |
|---|---|
| Other names | Spoon nails |
 | |
| Koilonychia | |
| Specialty | Dermatology |
Koilonychia, also known asspoon nails,[1]: 782 is anail disease that can be a sign ofhypochromicanemia, especiallyiron-deficiency anemia.[2]: 656 [3] It refers to abnormally thin nails (usually of the hand) which have lost their convexity, becoming flat or even concave in shape. In early stages nails may be brittle and chip or breakeasily.
Koilonychia is associated withPlummer–Vinson syndrome and iron deficiency anemia. It has also been associated withlichen planus,syphilis, andrheumatic fever. The term is from Greek κοῖλος (koilos) 'hollow' and ὄνυξ (onyx) 'nail'.
Even though koilonychia has been associated with iron deficiency in case reports, it is more likely seen as an occupational change in nails and may be idiopathic; ruling out iron deficiency anemia in these patients is the only work-up necessary in this condition.[4]