Splinters, Thorns, and Other Foreign Bodies in the Hand

Wood splinter in a finger
Figure 1. A wood splinter in the finger is a biological foreign body and can cause inflammation, making the area red, swollen, warm, and painful.

A foreign body is an object that ends up in the body. Objects intentionally placed for medical reasons, such as a joint replacement or a screw used to treat a fracture, are called medical devices rather than foreign bodies.

Foreign bodies can be biological or non-biological. Biological foreign bodies come from living things such as plants, animals, or insects. Examples include wood, thorns, teeth, insect stingers, sea urchin spines, coral, and stingray spines. Non-biological examples include glass, metal, gravel, bullets, BBs, shrapnel, fishhooks, pencil graphite, plastic, and fiberglass threads.

Causes

Foreign bodies can enter the hand or finger during puncture wounds, cuts, or lacerations. Home activities, gardening, exercise, recreation, fishing, diving, hunting, and certain jobs can all lead to foreign body injuries.

Examples include pencil graphite lodged in a finger, broken glass from a dish, wood splinters or thorns from gardening, gravel after a fall while running or cycling, sea urchin spines during snorkeling, fishhooks while fishing, or metal or wood shards from workplace tools.

Symptoms

Sometimes patients can tell there is a foreign body because of how the injury happened and how the area feels. It may feel like something sharp is poking the skin or like something is present that does not belong.

When the foreign body is near the skin surface, it may be visible. If it is pushed deeper, it can be difficult to confirm during an exam. A puncture wound, cut, or bleeding after an injury may raise concern that a foreign body is present.

  • A narrow area of tenderness when pressed
  • Sharp pain with pressure on the skin
  • A firm lump under the skin
  • Bruising
  • Pain with joint motion
  • Numbness if the foreign body is in or near a nerve
  • Redness, swelling, warmth, or signs of infection

Diagnosis

If the location of a foreign body cannot be confirmed by exam, imaging tests may help. X-rays are often the first test ordered. Some metals, teeth or tooth fragments, some fish spines, gravel, some plastics, coral pieces, and some glass may be visible on x-rays. However, a normal x-ray does not rule out all foreign bodies.

Ultrasound can be a useful test for detecting wood, thorns, and other materials. It can help determine whether there are one or multiple foreign bodies and can show size, shape, location, direction, and depth. Ultrasound can also detect surrounding soft tissue changes or fluid that may suggest an abscess.

CT scans and MRI may also show foreign bodies, especially when the object is deeper or near bone.

Treatment

Treatment depends on the type of foreign material, its location, symptoms, and the likelihood of infection. Foreign bodies from plants, bite wounds, and marine creatures are more likely to cause reactions or infections. Glass, metal, and plastic are less likely to cause inflammation or infection because they are synthetic materials.

When removal may be needed: pain, suspected infection, pressure on nearby tendons, nerves, or joints, and sharp materials near important structures are common reasons to remove a foreign body.

Deep foreign bodies that are not causing symptoms and are not reactive may sometimes be monitored with office exams. Foreign bodies close to the skin, tendons, nerves, or joints may need removal because they can cause pain or further injury.

During removal, the doctor may obtain a culture if infection is suspected. Antibiotics may be prescribed based on the type of wound and likely organisms. Human, dog, or cat bites often require different antibiotics than thorn punctures. Marine animal injuries may involve different organisms than land animal injuries.

Infection and Deeper Injury

Abscesses or deeper fluid collections may require surgical drainage and antibiotics. Infected joints, tendons, or bones require more involved treatment and sometimes intravenous antibiotics for several weeks.

Nerve injuries usually require exploration and repair, though residual numbness or weakness may still occur. Partial tendon tears may heal without surgery but can develop scarring that limits motion. Completely severed tendons often cause immediate motion loss and may require repair after infection concerns are addressed.

Delayed Lumps After Puncture Wounds

Months or years after a puncture wound, a lump can form. The patient may not remember the injury. Common post-traumatic masses include epidermal inclusion cysts and pyogenic granulomas. A pyogenic granuloma is a raised red lump that bleeds easily and may require removal and cauterization.

This mobile-friendly version is adapted from patient education content originally provided by the American Society for Surgery of the Hand.