Very rare familial spoon nails (Koilonychia).

An 85‐year‐old woman presented with platonychia and koilonychia (spoon‐shaped nails) of the fingers and toes which were present since her early childhood (Figure 1A and B). On physical examination, all her fingernails were spoon‐shaped with rough and darkened distal edges. Her toenails were thin and flat, except for the nails of the big toes, which exhibited the same abnormalities as the fingernails. Laboratory studies were negative for iron deficiency anemia and thyroid abnormalities, while those resulting in acquired koilonychia. Microscopic examination of both the fingernails and toenails were negative for fungi. A detailed family history of the patient revealed familial occurrence of abnormal nails in her grandfather, father, daughter, and son. Therefore, based on the detailed family history, including pedigree, familial koilonychia was diagnosed.1, 2, 3, 4 In cases in which the cause is unknown even after differential diagnosis of systemic diseases that frequently present with koilonychia, the possibility of hereditary/familial koilonychia should be considered.

Figure 1

Spoon nails of the patient

Conflicts of Interest

The authors have stated explicitly that there are no conflicts of interest in connection with this article.