Fast Five Quiz: Fingernail and Toenail Conditions

William James, MD


February 07, 2020

Factors implicated in the development of ingrown nails include:

  • Drugs: Indinavir has been reported to have an association with increased incidence of ingrown nails. Cyclosporine, docetaxel, oral antifungals, and retinoids can cause excess nail fold granulation tissue and eventual ingrown nail development.

  • Trimming toenails improperly: Cutting the toenail rounded, V-shaped, or too short will cause bulging of the soft tissue and the possibility of leaving a nail spur that is difficult to remove, resulting in an inflammatory reaction with pressure necrosis. The proper way to trim the toenail is to cut it straight across beyond the nail bed.

  • Poorly fitting shoes: The nail plate can be forced out of the nail groove by footwear that has a toe box that is too small for the forefoot. The constant pressure on the nail bed and nail groove results in breakage that starts an inflammatory process and eventually results in an ingrown nail.

  • Nail plate abnormality: Increased curvature of the nail plate, as in pincer nail, may develop into an ingrown nail. Deformities that result from prior trauma or underlying bone pathology may predispose to ingrown nails.

  • Excessive sweating: Ingrown nails are common among people with excessive sweating, which results in softening of the nail fold.

  • Generalized joint hypermobility: Joint hypermobility through changes in foot biomechanics and gait changes increases medial midfoot pressure and loading during walking; as the first metatarsophalangeal joint bears the most pressure, an ingrown toenail may develop in the big toe.

  • Onychomycosis: This infection may result in brittle nails, which may form nail spicules and pierce the adjacent nail fold.

  • Heredity: Some people are genetically predisposed to inwardly curved nails, with distortion of one or both nail margins.

  • Hematopoietic stem cell transplantation

  • Diabetes

Read more about ingrown nails.


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