Soft tissue foreign bodies may be encountered when managing new wounds or evaluating complications of old wounds. This chapter discusses methods of detecting and removing them.
Methodically search fresh wounds for contamination by foreign material. If a foreign body is discovered within a wound cavity or deeply embedded in tissue, decide if removal of the material is urgent, can be delayed, or is even necessary. The decision to remove foreign bodies located below the dermal layer of skin depends on the size, location, composition, accessibility, and anticipated mechanical and inflammatory effects of the object. Many foreign bodies should be removed in the ED. For example, all foreign material within the cavities of fresh lacerations should be irrigated away, debrided, or extracted with instruments. Occasionally, patients with subcutaneous foreign bodies should be referred to appropriate specialists for delayed removal.
Most foreign bodies are detectable during clinical examination.1,2 Imaging studies are used to evaluate wounds when a concealed object is possibly present.3
Transient inflammation is an integral part of normal wound healing. A small amount of foreign debris in a wound provokes an inflammatory response in an effort to eliminate or contain the invader. Large quantities of devitalized tissue, foreign debris, bacteria, or other irritants present within a wound intensify this protective response. Excessive or prolonged inflammation delays wound healing and destroys surrounding soft tissue and bone, producing periosteal reactions, osteolytic lesions, synovitis, and arthritis. If the body fails to dissolve or extrude foreign material, it may become encapsulated within a fibrous capsule. Once a retained foreign body is encapsulated, inflammation subsides.
The type, timing, and intensity of an inflammatory reaction are determined primarily by the chemical composition and physical form of the foreign object. Material that is inert—such as glass, metal, or plastic—may not elicit any abnormal tissue response. Objects with smooth, nonporous surfaces produce less inflammation and fibrosis than those with rough surfaces. Most metals are inert, but those that oxidize will cause mild to moderate inflammation. Earrings with studs dipped in gold paint cause earlobe swelling and inflammation when the paint flakes off. Vegetative foreign bodies, such as wood, thorns, and spines, trigger the most severe inflammatory reactions. Sea urchin spines, other marine foreign bodies, and hair may cause chronic inflammation with granuloma formation.
In some cases, inflammation is caused by a local toxic reaction. For example, blackthorns contain an alkaloid that produces intense inflammation. The oils and resins in redwood and cedar splinters also cause considerable inflammation. Sea urchin spines and catfish spines contain venom that causes severe burning pain at the puncture site and a variety of systemic symptoms (see chapter 213, "Marine Trauma and Envenomation"). A sudden, local inflammatory reaction from a rose thorn or cactus spine may be an allergic response to fungi on the plant. Some cacti cause a delayed hypersensitivity ...