Causes of fingered nails .. Redness of blood. Black Shakes. Plummer Vinson's syndrome. Petroleum Vaseline Derivatives. Strong alkali is like a thorn

Spoon nails:
The nail is thin and concave by the side with the inverted edges.

Causation:
- Iron deficiency.
- Redness of blood.
- Acute diseases (coronary artery disease).
- Syphilis (syphilis).
Black Sharks.
Blamer Fenenson syndrome.
- Strong alkali such as thorns.
- Petroleum Vaseline derivatives.