A 19-year-old boy was seen on July 18, 1961, for a disorder of 5 weeks' duration involving 3 nails of his right hand. Two nails were absent. They had been loose and had been pulled out by a physician. A third nail was separated from the bed, but still hanging on. The boy complained of numbness, of dropping glasses because of lack of feeling on his fingertips.
He worked as a cropper for a chicken processing concern. Since May, 1961, he had used 3 bare fingers of his right hand to remove 2,800 chicken feedbags (crops) per hour every working day. The rest of the fingers were not involved in the operation, but an abnormality of the distal end of each nail was noticeable. The edges were split in thin layers, an exfoliative disorder analogous to the formation of scales in the skin. This is called onychoschizia lamellina, also onychorrhexis
RONCHESE F. Nail Defect and Occupational Trauma. Arch Dermatol. 1962;85(3):404. doi:10.1001/archderm.1962.01590030102015
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