Subungual foreign bodies are often difficult to treat. Foreign
bodies such as wood or metal splinters, pencil lead, thorns, spines,
or hair may become lodged beneath the fingernail.1–3 Tradesmen
such as carpenters, landscapers, auto mechanics, and individuals
who work without hand protection with materials that produce small
splinters are at risk for this type of injury. Subungual foreign
bodies may also present less commonly under the toenails.
Patients generally present for medical intervention complaining
of pain after unsuccessfully attempting to remove the foreign body.
Prior removal attempts often result in breakage of the foreign body
or pushing it further beneath the nail; both of which complicate
the next extraction attempt. Left untreated, retained subungual
foreign bodies will often become infected or cause tissue reactions
and granuloma formation. These injuries may be treated rapidly with
complete removal of the foreign body and without causing additional
The distal fingertip and nail apparatus are complex structures
(Figure 86-1). The perionychium is composed of the nail bed and
the surrounding soft tissue. The hyponychium is the junction of
the nail bed at the sterile matrix and the fingertip skin beneath
the distal margin of the nail plate. The eponychium is the distal
portion of the nail fold where it attaches to the proximal surface
of the nail plate. The lunule is the white arc seen on the proximal
portion of the nail plate. The nail bed consists of the germinal
matrix on the proximal ventral floor of the nail fold and the sterile
matrix that extends from the lunule to the hyponychium. The germinal
matrix is primarily responsible for the growth of the nail. The
subungual space is the area immediately beneath the nail plate.
The anatomy of the distal fingertip and nail bed. A. Surface anatomy. B.
Foreign bodies may enter the subungual space at the distal fingertip
beneath the nail, or may penetrate the nail plate directly (Figure
86-2). In either event, separation of the nail from the nail bed results
in severe pain. Patients generally immediately attempt to remove
the foreign body because of this intense pain. Infection or foreign
body reaction is likely to ensue if the foreign body is not removed
in its entirety.
Subungual foreign bodies can enter from under the distal
nail plate or through the nail plate.
Subungual foreign bodies should be removed to prevent the complications
of infection, foreign body reaction, and possible nail deformity.
Deeply embedded foreign bodies, splintered foreign bodies, those
that traverse the nail plate, or contaminated foreign bodies may
require the removal of the nail plate to extract the foreign body.
Refer to Chapter 87 regarding the details of removing the ...