Infection
Signs include redness, tenderness, swelling (often more apparent
on the back of the hand), lymphangitis — streaks of red running up the
arm — and lymphadenopathy (epitrochlear or axillary). Many hand
infections will settle within 24—48 hours if elevated, splinted and treated
with a best-guess antibiotic. As soon as the signs of inflammation have settled,
the hand must be diligently mobilised. If pus appears, it must be drained; the
wound should be left open, antibiotics changed according to microbiological
advice, and the hand splinted in the Edinburgh position and then mobilised as
soon as the inflammation settles.
Acute
paronychia
This is the most common infection of the hand, often caused by careless
nail trimming or picking the skin around the nail fold (Fig.
30.12). After an
initial inflammatory phase,
Chronic
paronychia
This appears over several weeks (Fig. 30.13). Rather than a consequence
of an acute paronychia, it is usually a chronic fungal infection in those
with their hands constantly immersed. Microscopical examination of the scrapings
and special fungal cultures will confirm the diagnosis. It may resolve if the
hands are kept dry and the nail fold is regularly dressed with antifungal
ointment. If this fails, the nail fold is laid open.
Pulp
space
Otherwise known as a ‘felon’, this causes severe pain in the
finger pulp. Pus is trapped between the fibrous septae which bind the
specialised fingertip skin to the underlying bone; the bone of the terminal
phalanx can also become infected leading to a sequestrum. An abcess should be
drained through an oblique incision over the point of greatest tenderness. The
differential diagnosis is a herpetic whitlow. This is caused by herpes
simplex virus and may be found, for example, in dental workers. Small vesicles
appear which then become crusty. Surgery should not be performed; it resolves
itself over a few weeks.
Flexor
tendon sheath infection
There is little spare space within the tendon sheath; an untreated
infection rapidly causes adhesions and even tendon necrosis, leading to a stiffs
useless finger. The classic signs, described by Kanavel, are a swollen finger
held in flexion, with exquisite pain on passive extension and tenderness
precisely over the flexor sheath. The usual organism is a Staphylococcus
or a Streptococcus. The tendon sheath should be
Serious infection and subsequent loss of function can result from animal
or human bites. Human organisms include Eikenella corridens; animal bites
include Pasteurella multicodens. Staphylococci are common in both.
These organisms are usually sensitive to broad-spectrum antibiotics such as
Augmentin. Wounds should be explored under adequate analgesia and a tourniquet.
A common injury is over the knuckle when the opponent’s tooth penetrates the
metacarpophalangeal joint. The penetration may not be apparent because the
four layers (skin, tendon and capsule and synovium) which are injured in flexion
close over when the knuckle is examined in extension. The wound must
be excised, the joint thoroughly washed out, and the extensor tendon repaired
and splinted.
Other
infections
Mycobacterial
infections
Tuberculosis in the hand may involve the tenosynovium, joints or bone.
The most dramatic is a so-called compound palmar ganglion, with synovial
swelling both proximal and distal to the transverse carpal ligament. The
diagnosis is confirmed by biopsy. Treatment is by synovectomy and prolonged
drug treatment.
Pilonidal
sinus
A hair implanted in the palm or web space can cause a cyst with
recurrent infection (Fig. 30.14). The cyst should be excised.
Orf
Transmitted by sheep, this virus causes red papules which become reddish
blue and then grey nodules. The condition resolves after a few weeks.
Palmar
space infections
Pus can collect deep to the palmar fascia either side of the septum
running down to the third metacarpal. The whole hand is swollen and the palm
intensely tender. The infection is drained through a longitudinal incision,
great care being taken to avoid damage to the tendons, nerves and blood vessels.
Web
space infections
Pus can collect in the potential space surrounding the lumbrical
muscles as they pass from the palm, across the deep transverse metacarpal
ligament into the extensor mechanism. The swelling in the web space tends to
spread the adjacent fingers apart. The pus is drained through a longitudinal
incision over the web space, taking care not to damage the nearby neurovascular
bundles.