[Onychopathy of mushroom-growers].

Particular nail damage appeared in patients working on mushroom beds. In five cases, all similar, the recent use of plastic bags containing the growing medium, seems to be the origin of this onychopathy. Onycholysis with latero-distal "usure des ongles", koilonychia, longitudinal splitting with sometimes splinter haemorrhages are the most specific changes. Chemical damage by phytosanitary products or fungi infection have no significant part in these abnormalities; their cause is traumatic, representing occupational stigmata mark, and results from repeated rubbing of the nails in workers lifting up heavy plastic bags.