Foreign bodies embedded in the foot are common in podiatry. The patient may or may not recall the incident. There are number of objects that can penetrate the skin of the foot causing an embedded foreign body. The most common foreign body to penetrate the foot is a sewing needle. There are other materials that can cause foreign body injury to the foot including; toothpicks, glass shards, metal shavings, cloth fibers, hair, and sand or silica. Most anything that is hard can penetrate the skin and pose a threat when it is stepped on by the foot. Insect stings and sticker-burrs from various plants are also common.
Foreign bodies can remain in the foot indefinitely. There have been reports of materials that have penetrated the foot and have remained encapsulated in deep tissues of the foot for years. Usually, the body will see the foreign object, no matter how small, and encapsulate it through an immune tissue response. Many times, it’s not the foreign body, but the foreign body tissue response that causes pain and the need for removal.
All foreign body penetrations are considered “dirty” and present risk of infection. The most common organisms found are staphylococci. Deep penetration injury should be treated with the appropriate antibiotics. Early removal of the deep foreign bodies will lessen the degree of infection and abscess. A complete history of the injury is important, including when, where, and how the injury occurred. Patients will often remove part of the foreign body material and leave material behind. The type of injury and placement of the foreign body will usually dictate treatment. Joint penetrations are considered surgical emergencies requiring hospitalization and removal of the foreign body material. X-ray of the injury remains the standard exam for localizing penetration injuries of the foot.
Treatment is dictated by presenting symptoms. In most cases, foreign bodies can be retrieved in the office setting. Tetanus immunization must be up to date. The severity of a foreign body injury is directly equivalent to the depth of the injury. Deep penetrating wounds need to be open and treated aggressively to prevent abscess and system wide infection. Another factor that determines severity of the injury is “cleanliness” of the foreign body material. If you suspect a foreign body or foreign body reaction, seek treatment.