Fingernails can become ingrown, a condition formally known as onychocryptosis, though it is far less common than its counterpart in the feet. This condition occurs when the edge of the nail plate grows into the surrounding soft tissue, or periungual skin. This leads to inflammation and discomfort. While most people associate ingrown nails with the toes, the mechanics of nail growth mean that any nail can potentially embed itself into the flesh.
Why Fingernails Rarely Become Ingrown
The rarity of ingrown fingernails is primarily due to fundamental anatomical and mechanical differences between the hands and feet. Toenails are constantly subjected to external forces, particularly the downward pressure from walking and the lateral squeeze of footwear. Fingernails, by contrast, are generally not confined by shoes, eliminating the primary external factor that drives the nail plate into the skin.
Furthermore, the shape and growth characteristics of fingernails offer greater protection. Fingernails grow faster than toenails, averaging about 3.5 millimeters per month, and are typically thinner and more flexible. This combination helps the nail maintain a flatter contour, which reduces the likelihood of the edges curling sharply inward.
The structure of the lateral nail folds also plays a role. On fingers, these folds are not routinely pressed upward against the nail with the same intensity as they are on the toes during weight-bearing activities. The overall environment of the finger, which is usually drier and less subject to sustained mechanical compression, makes it less prone to the nail plate penetrating the skin.
Common Causes of Ingrown Fingernails
When an ingrown fingernail does occur, it is often precipitated by direct trauma or improper care rather than the structural issues common to the feet. Improper trimming is a frequent trigger, particularly cutting the nail too short or excessively rounding the corners. Trimming the nail plate deep into the lateral grooves can leave behind a small, sharp spicule, which then grows forward and pierces the sensitive skin.
Habitual hand trauma is another major contributing factor, especially nail biting or aggressively picking at the sides of the nail. These actions can damage the nail fold, providing an entry point for the nail edge to embed. Similarly, overly aggressive manicuring, such as pushing the cuticle back too forcefully or trimming the lateral folds, can disrupt the protective integrity of the skin barrier.
Repeated, localized physical pressure, often related to occupation, can also cause the nail to curve unnaturally. Activities like constant typing, playing string instruments, or applying sustained pressure with a pen can reshape the nail plate over time. In some cases, the cause is an underlying nail dystrophy, such as a pincer nail deformity, where the nail plate has an exaggerated transverse curvature, making it predisposed to growing inward.
Recognizing and Treating the Condition
The initial signs of an ingrown fingernail are similar to those in the toe, beginning with tenderness along the side of the nail. This progresses to redness, swelling, and localized pain, which worsens with pressure or touch. If the condition is left unaddressed, the area can become infected, showing signs like warmth, increased swelling, and the discharge of pus, a secondary infection medically termed paronychia.
For mild cases, home treatment can be effective by reducing inflammation and encouraging the nail to grow out. Soaking the affected finger in warm, soapy water for 15 to 20 minutes, two to three times a day, can soften the skin and provide symptomatic relief. After soaking, gently lifting the nail edge and placing a small piece of clean cotton or dental floss beneath it can help guide the nail over the skin fold.
Prevention centers on correcting the trimming technique. Nails should be cut straight across, avoiding the temptation to curve the edges or trim them shorter than the tip of the finger. If signs of infection develop, such as persistent pain or yellowish discharge, it is important to seek medical attention. Individuals with underlying health issues like diabetes or poor circulation should consult a healthcare provider immediately, as they are at a higher risk for serious complications.