Persistent occupational koilonychia.
D006801:Humans; D008297:Male; D008875:Middle Aged; D008899:Mineral Oil / Q000009:adverse effects; D009264:Nails, Malformed / Q000209:etiology*; D009784:Occupational Diseases / Q000209:etiology*; D013314:Stress, Mechanical
D008899:Mineral Oil