koilonychia

A malformation of the nails in which the outer surface is concave; often associated with iron deficiency or softening by occupational contact with oils. SYN: spoon nail. [G. koilos, hollow, + onyx (onych-), nail]

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koil·onych·ia .kȯil-ō-'nik-ē-ə n abnormal thinness and concavity of fingernails occurring esp. in hypochromic anemias called also spoon nails

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n.

the development of thin (brittle) concave (spoon-shaped) nails, a common disorder that can occur with anaemia due to iron deficiency, though the cause is not known. Any underlying disease should be treated.

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koi·lo·nych·ia (koi″lo-nikґe-ə) [koil- + onychia] a type of dystrophy of the fingernails in which they are thin and concave and have raised edges; it is sometimes associated with iron deficiency anemia. Called also spoon nail.

Koilonychia (left).