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 and a variety of
systemic symptoms (see Chapter 207, Trauma and Envenomations from Marine Fauna). 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
reaction. Systemic toxic and allergic reactions are unusual but
serious complications of foreign bodies. Although toxicity is unlikely,
foreign bodies containing lead, such as bullets, have the potential
to produce systemic lead poisoning, particularly if they are in
contact with pleural, peritoneal, cerebrospinal, or joint fluid.5,6
Infections are the most common complication of retained foreign
bodies. Foreign bodies may incite a variety of soft tissue inflammation
and infections, including local wound infection, cellulitis, abscess
formation, lymphangitis, tenosynovitis, bursitis, septic arthritis,
and osteomyelitis.7–9 Infections associated
with retained soft tissue foreign bodies are characteristically
resistant to therapy; antibiotics, anti-inflammatory drugs, and steroids
may produce a partial regression of symptoms but seldom eradicate
the infection.10 Some infections will resolve spontaneously
once the foreign bodies are removed. Bacteria are infrequently detected
after plant thorn injuries, possibly due to the empiric use of antibiotics,
but when bacteria are found, Pantoea agglomerans is
the most commonly reported isolate.11,12 Vegetative
foreign bodies may also cause fungal infections, particularly in
Foreign objects can also cause mechanical damage by compressing
or lacerating anatomic structures or occluding vessels. Repeated
movement of tissue containing a foreign object increases the fibrous
Every wound has the potential for concealing
a foreign body, but only a small percentage of lacerations and puncture
wounds actually contain them.2,3,13,14 Certain
historical factors are associated with a higher risk for a retained
foreign body: the mechanism of injury, composition and shape of
the wounding object, and the shape and location of the resulting wound.1,13,14 Objects
that shatter, splinter, or break in the process of causing a wound
often leave remnants behind. For example, a wound caused by glass
that broke on the skin is more likely to contain shards than a wound
caused by previously broken glass. Dental fractures after a blow
to the mouth may be the only sign that fragments of teeth are embedded
in the lip or tongue of the patient or in the hand of the assailant.15 Thorns,
spines, and sharp wooden branches are usually brittle and tend to
penetrate deeply into puncture wounds before breaking. Wood splinters
are notorious for fragmenting, especially when they are pulled out
of a puncture wound.
Patients impaled by long, thin metallic objects, such as hypodermic
or sewing needles, may remove them without realizing that a portion
of the object broke off beneath the skin surface. Both remnants
of a needle and impurities in street drugs can cause persistent
pain or abscess formation at the site of IV drug use. Nails that
penetrate socks and shoes may drive leather, rubber, or cloth into
the plantar surface of ...