Hand infections are frequently encountered in the primary care setting, where general practitioners (GPs) play a key role in early recognition, diagnosis and treatment. Early detection and management can prevent infections that may lead to prolonged hospitalisation or disability.
Hand infections are common presentations in the
acute care setting. The exact incidence of hand
infections is difficult to determine as most are self-treated
or treated by primary care physicians.
However, it is estimated that a major metropolitan
hospital can expect 25 to 50 admissions a year for serious hand infections.1
Why early detection is important
While some hand infections may appear innocuous
or mild in the early stages, they can rapidly progress to devastating infections
requiring surgical debridement, resulting in
prolonged hospital admission. Hence, it is
essential to recognise and diagnose these
infections early and promptly initiate treatment.
In addition, these hand infections can lead to tissue loss, functional impairment and even permanent disability if left untreated.
The spectrum of hand infections can range from finger infections to deep space infections, caused
by many microorganisms – depending on the mechanism of injury, inoculation or occupational
exposure. An estimated 65% of hand infections are caused by aerobic organisms, of which 60% are
pure gram-positive, and 5% are pure gram-negative.1
The principles of managing infections are:
This article will focus on common hand
infections such as:
Paronychia is an infection of the lateral nail fold surrounding the nail. It may be acute (duration of less than six weeks) or chronic
(duration of six weeks or more).2
Presentation and diagnosis
This presents with erythema, swelling,
tenderness and occasionally spontaneous
discharge of purulent material. It occurs after
disruption of the seal between the nail fold
and nail plate due to penetrating trauma, nail-biting,
manicures or hangnails.
In the early stages of paronychia, patients
can be treated with warm soaks, systemic
oral antibiotics and resting the affected
digit. The antibiotic regimen should cover
If there is a superficial abscess, early drainage
is advised by incision of the paronychia fold
with a blade directed away from the nail bed
In cases with subungual pus, nail avulsion
should be performed under a digital block.3
The pus within the perionychium may track
volarly to the pulp space presenting with a
pulp abscess or felon.
Felon is the second most common hand
infection, comprising around 15-20% of cases.4
It is defined as a closed-space subcutaneous
infection in the pulp space of the distal
phalanx of a digit.1
Presentation and diagnosis
There is typically a history of penetrating injury
preceding a felon. Symptoms include a tense
and tender pulp with erythema and swelling
that usually does not extend proximally past
the distal interphalangeal joint (DIPJ) flexion
However in severe cases, felons can rupture
the DIPJ, causing septic arthritis, and extend
into the distal end of the flexor tendon
sheath, causing flexor tenosynovitis.1 A finger
radiograph is essential to rule out osteomyelitis
of the distal phalanx.
Early felons may be treated with antibiotics,
rest and elevation.
The most common microorganism involved is
Staphylococcus aureus, but various aerobic
and anaerobic organisms can cause felons.
Thus, broad-spectrum antibiotic therapy is
However, a tense pulp with the presence
of subcutaneous collection is an indication
for surgical drainage. A longitudinal midline
incision over the pulp area of maximal tenderness
is usually made to drain the collection.
The pulp septae should be surgically released
as well to ensure no hidden collection that
may be missed.
The wound is then left open and dressed with
a sterile dressing. Dressing changes should
be performed every 24-48 hours using sterile
soaks and Jelonet dressing. The wound may
be left to heal by secondary intention.
Flexor tenosynovitis is a closed space infection
of the digital flexor tendon sheath.
This is often accompanied by a history of
penetrating injury to the digit, with Staphylococcus
aureus being the most common
In 1912, Allen Kanavel described four cardinal
signs indicative of flexor tenosynovitis:5
Factors that predict poor outcomes include:
The presence of digital ischaemia and
subcutaneous purulence increases the risk of
amputation to 59%.6
Laboratory investigations may reveal raised
inflammatory markers, and the patients may
be bacteraemic. Infection of the flexor tendon
sheath for the thumb and little finger may
spread proximally to the space of Parona and
form a horseshoe abscess.
Early management includes intravenous
antibiotics and elevation. In addition, surgical
drainage is indicated, especially with suppurative
Figure 4 shows a closed tendon sheath
irrigation using an infant feeding catheter.
However, in the presence of severe infection
with tendon necrosis, open debridement is
Septic arthritis in the hand or wrist results
from a puncture wound or an extension
of an adjacent tendon sheath infection,
subcutaneous abscess or bone infection.
These can lead to the destruction of the
joint and osteomyelitis of the phalanges or
It can occur following a ‘fight bite’ or an
Most human bite infections result from a
‘clenched fist injury’ – a laceration over the
dorsal metacarpophalangeal joint (MCPJ) from
striking teeth with a clenched fist. A tooth can
easily penetrate the MCPJ capsule, leading to
septic arthritis if left untreated.1
Dog and cat bites account for more than
90% of all animal bite wounds. Patients with
animal bites tend to present late, as these
wounds may seem innocuous in the early
stages. However, they may have raised
inflammatory markers, and plain radiographs
may reveal remnant foreign bodies, cortical
breaks and bone erosions.
Patients with septic arthritis typically present
with a swollen, erythematous and painful
joint. Needle aspiration of the joint helps establish the diagnosis and identify the
Eikenella corrodens is most associated with
human bite infections. The most common
pathogens cultured from the dog mouth are
Staphylococcus aureus, Streptococcus viridans,
Bacteroides and Pasteurella multocida.
Pasteurella multocida is especially common in
The initial treatment for animal bites should
encompass an update of tetanus immunisation
and identifying the rabies immunisation status
of the animal.
Prompt and thorough irrigation of the wound
should be performed after obtaining wound
cultures, in addition to broad-spectrum
empirical antibiotics cover.
Bite wounds over the hand and wrist joints
should be treated as septic arthritis until
proven otherwise. Early surgical debridement
and joint irrigation are advised.
Figure 5 shows a technique of catheter
irrigation of a septic joint of the hand. We
routinely perform continuous catheter irrigation
for at least five days from the initial
debridement. In some cases, open debridement
and eventual amputation may be necessary.
The antibiotic duration varies from ten days
to six weeks, depending on the organism
involved and the clinical improvement of the
Hand infections are frequently encountered
in the primary care setting. Early recognition,
diagnosis and treatment are crucial to
prevent further progression of infection and
A thorough medical history, especially for
diabetes mellitus, and circumstances of
the injury are essential parts of the history
Patients should be promptly referred to the
Emergency Department at your nearest
hospital for further assessment and
surgical management by a hand specialist
when in doubt.
Early rehabilitation by performing active
and passive motion exercises to prevent
joint stiffness is vital for optimum patient
Dr Chung Sze-Ryn is an Associate Consultant in the Department of Hand & Reconstructive
Microsurgery at Singapore General Hospital (SGH). She graduated from the Royal College
of Surgeons, Ireland in 2011 and achieved her MRCS (Edinburgh) and MMed (Surgery) in
2013 and 2016 respectively. Dr Chung completed her Hand Surgery Residency in 2020 and received the Outstanding
Resident award in her final year. She is currently a clinical instructor at Duke-NUS Medical
School and a clinical physician faculty member for the SingHealth Hand Surgery Residency
She has also been published in many distinguished peer-reviewed journals and was actively involved in the grant collaboration between the SGH Hand & Reconstructive
Microsurgery Department and Nanyang Technology University (NTU-SACP grant). She
recently won a grant of 150,000 SGD from the SingHealth Duke-NUS Academic Medical
Centre to do animal research on the process of adhesion formation and its impact on
clinical outcomes. Dr Chung has a special interest in reconstructive microsurgery of the
extremities as well as wrist disorders.
Dr Farah Syahera binti Khairi
is a Medical Officer in the Department of Hand & Microsurgery at Singapore
General Hospital. She graduated from the National University of Ireland, Galway in 2016. Throughout her journey as a junior doctor, she has done predominantly surgical postings.
She has a special interest in hand surgery and is a hopeful candidate for the Residency
Programme this year.GP Appointment Hotline: 6326 6060