Soft tissue foreign bodies may be encountered when managing new wounds
or evaluating complications of old wounds. This chapter discusses
the effects of foreign bodies on soft tissue and methods of detecting
and removing them.
When evaluating fresh wounds, methodically search for contamination by
foreign material. If a foreign body is discovered within a wound
cavity or deeply embedded in tissue, the clinician should 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 physicians for delayed removal.
Most, but not all, foreign bodies are detectable during clinical
examination.1–3 Various imaging studies
can be used to evaluate wounds when nothing is found during exploration,
but the possibility of a concealed object exists.4 However,
some foreign bodies may be invisible to radiographic or sonographic
study, so patients should be informed of this possibility and receive
appropriate discharge instructions.
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. When large quantities of devitalized tissue, foreign
debris, bacteria, or other irritants are present within a wound,
this protective response intensifies. Excessive or prolonged inflammation
may delay wound healing or destroy surrounding soft tissue and bone,
producing periosteal reactions, osteolytic lesions, synovitis, and
arthritis. If the body fails to dissolve or extrude foreign material,
it will 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 ...