Deformed nail: a connection with eczema?

The nail is a protective layer additional to the skin on the fingers, primarily composed of hardened dead cells containing keratin. It shields the fingertip from various chemical, biological, and mechanical traumas but can sometimes become deformed. The main causes of a nail's deformation are:

• A fungal infection.

  Nail fungal infections, also known as onychomycosis, occur when fungi penetrate the nail. These fungi thrive in warm and moist environments, such as inside shoes, and cause changes in the appearance and texture of the nail. They can notably thicken it, discolour it, and turn it yellow or brown or deform it.

• A trauma.

  Repeated trauma or a direct impact on the nail can damage the nail matrix, which is responsible for its growth. This can result in deformities, such as excessive curvature or cracking of the nail.

• Some skin diseases.

  Some skin conditions, such as psoriasis and lichen planus, can affect the nails and cause deformities. In psoriasis, for instance, extra skin cells build up and form thick, rough patches on the nail, which can then lift or detach. Lichen planus, on the other hand, can cause streaks or grooves on the nails.

• Some diseases systemic.

  Medical conditions such as arthritis, diabetes, hypothyroidism, or circulatory disorders can disrupt nail health. Inflammatory arthritis can lead to chronic inflammation around the nail, causing its deformation. Diabetes, on the other hand, can affect blood circulation and nerves, which can lead to changes in the thickness or curvature of the nails.

• Genetic factors.

  Some individuals may have a genetic predisposition to nail abnormalities, such as onychodystrophy. This can manifest as fragile, brittle, thick or misshapen nails from birth or develop progressively over time.