Definition: Spoon-shaped or concave nail growth. The nail may also have raised longitudinal ridges and may be thin or brittle.
Causes: Iron deficiency anaemia may cause thin, brittle and/or ridged nail appearance. Koilonychia typically appears as concave nail growth and may present also as flat nail growth.
Examination: Examine the patient’s hands carefully. In long standing iron deficiency anaemia, nails eventually lose their normal convexity and develop spooning. This occurs in both finger- and toe-nails. Other clinical signs of iron deficiency anaemia include: angular stomatitis and painless glossitis.