Occupational Nail Disorders With a Reference to Koebner's Phenomenon

Abstract

Koebners' phenomenon refers to the presence of certain underlying diseases that may result in replication and aggravation of that disease in the area of injury. Psoriasis and lichen planus are classic examples of diseases in which the Koebners' phenomenon often produces nail involvement in patients with psoriasis or lichen planus. Certain traumatic occupations that involve repetitive trauma to the nails may produce such severe psoriasis or lichen planus that the nails are practically destroyed. Indeed, it may be advisable to instruct psoriatics not to enter jobs in which mechanical trauma is obvious such as pressure and friction. Even if the patient's psoriasis or lichen planus is only in a latent form, careful consideration should be given to the job placement of such individuals because severe psoriasis or lichen planus of the nails may be incapacitating and may become medicolegally significant. Exposure of the nails to certain chemicals with a resulting allergic reaction may produce severe destruction and even permanent loss of the nails. This has been shown to be due particularly to an allergic reaction to methyl methacrylate used in sculptured nails. Such allergic reactions may be accompanied by persistent paresthesia of the fingers. Nail “hardeners” such as formaldehyde may produce severe onychia and paronychia. Subungual keratoacanthomas a very painful condition that may require extensive surgery of the distal phalanax may be associated with foreign body injuries such as steel wool particles.