The nail bed, which includes the specialized tissue known as the sterile matrix, is the soft tissue structure directly beneath the nail plate. This area is responsible for maintaining the nail’s adherence and integrity as it grows forward. Injuries here are painful because the fingertip is densely packed with nerve endings and the tissue lies directly on the bone of the distal phalanx. Trauma, most commonly from crushing accidents like slamming a finger in a car door, or from sharp lacerations, can damage this delicate matrix. Such injuries frequently result in a subungual hematoma, a collection of blood trapped between the nail plate and the nail bed, causing throbbing pressure and intense discomfort.
Immediate Care Steps for Injury
Begin by gently washing the injured area with clean water and mild soap to remove any visible dirt or debris. If the nail plate is partially torn or jagged, carefully trim away loose pieces using sterile scissors to prevent further snagging and tearing of the underlying nail bed.
Control bleeding by applying gentle, direct pressure to the wound with a clean cloth or sterile gauze for 10 to 15 minutes. Elevating the injured hand or foot above the heart helps slow blood flow and reduce swelling. Once bleeding is controlled, protect the open wound with a non-stick dressing or a light layer of antibiotic ointment covered with a bandage.
To manage pain and swelling, apply an ice pack wrapped in a cloth to the injured area for 15 to 20 minutes at a time. Over-the-counter pain relievers, such as acetaminophen or ibuprofen, can reduce discomfort and inflammation. Remove all jewelry from the injured finger immediately, as rapid swelling can make rings difficult or impossible to remove later.
Deciding When to Seek Medical Attention
While many minor nail injuries can be managed at home, certain signs indicate the need for professional medical evaluation. Seek immediate care if:
- Bleeding cannot be stopped after applying direct pressure for 15 minutes.
- Visible bone or a deformed finger, suggesting a possible fracture of the underlying distal phalanx.
- The nail is completely detached, severely torn, or cut deeply, requiring assessment for proper repair.
- A large subungual hematoma covers more than 25% to 50% of the nail surface and causes significant throbbing pain.
- You are unable to move or straighten the injured finger normally, signaling potential damage to tendons or joints.
Common Professional Medical Procedures
The goal of professional treatment is to restore the anatomy of the nail bed to prevent future nail deformities. Trephination is a common procedure used to treat a painful subungual hematoma. This involves creating a small, sterile hole through the nail plate to allow the trapped blood to drain, immediately relieving the pressure and throbbing sensation. Trephination is often performed using a small needle or an electrocautery device, which rapidly melts a hole in the nail without touching the sensitive nail bed beneath.
For complex injuries, such as a deep cut or laceration, the nail plate is often gently removed to allow access for repair. The healthcare provider then uses very fine, absorbable sutures, such as 6-0 thread, to meticulously stitch the lacerated nail bed tissue back together. A tissue adhesive, often referred to as surgical glue, is sometimes used as an alternative to traditional sutures, offering comparable results with a faster repair time.
Splinting the Nail Bed
Following repair, a splint is placed to protect the delicate nail bed while it heals. The original, cleaned nail plate is the preferred biological splint, as it naturally fits the curvature of the nail bed and helps keep the proximal nail fold open. If the original nail is too damaged, an artificial nail or a sterile piece of plastic sheeting may be secured over the repair site. This splint acts as a protective barrier and prevents the nail fold from collapsing and adhering to the nail bed, which could cause a permanent split or deformed nail.
Recovery and Long-Term Aftercare
After a medical procedure, proper aftercare is necessary to encourage healing and minimize the risk of complications. The injured area must be kept clean and dry, especially in the initial days following the procedure. Patients should avoid submerging the digit in water, such as during a bath, and instead cover the hand during showering, as moisture can increase the risk of bacterial contamination.
Dressing changes should be performed daily or as instructed, using non-adherent gauze to prevent the dressing from sticking to the healing tissue. Monitor the wound for signs of infection, which may include increasing pain, spreading redness, warmth, or the presence of pus. A persistent fever can also signal a systemic infection that requires immediate medical attention.
Nail Regrowth Timeline
The timeline for complete recovery is lengthy because nails grow slowly, typically at a rate of a few millimeters per month. The new nail will grow out from the matrix, gradually pushing the injured or replaced nail plate forward. Full regrowth of a fingernail can take six months, while a toenail may take up to a year. Despite the best treatment, significant injury to the nail matrix can result in a permanent cosmetic change, such as a split nail or longitudinal ridging.