June 20, 2024

Hand infections can occur in any tissue of the hand with a variety of pathogens most commonly Staphylococcus aureus.

Hand Infections
Hand Infections

Anatomy of Hand

Palmar aponeurosis:

  • Fibrous in nature
  • Triangular
  • 4 digital bands attach to the base of the proximal phalanx

It is thin over thenar and hypothenar eminences

Fibrous digital sheath

It is a ligamentous tube that encloses synovial sheath, superficial and deep flexor tendons, and tendons of FPL

Medial fibrous septum

Medial border of palmar aponeurosis to 5th metacarpal

Medial to this is the Hypothenar compartment

Lateral fibrous septum

The lateral border of palmar aponeurosis to 3rd metacarpal

Lateral to it is the Thenar compartment

In between the thenar and hypothenar compartment is the central compartment which contains

  • Flexor tendons and sheath
  • Lumbricals
  • Superficial palmar artery arch
  • Digital vessels and nerves

Adductor compartment

Deepest muscle plane of the palm

Contains Adductor pollices

Compartments of hand
Compartments of hand

Radial Bursa

It is the continuation of the flexor pollices longus tendon sheath through the flexor retinaculum to the point 2.5 cm above the wrist joint

Superiorly continuous with common sheath

Inferiorly up to distal phalanx of thumb

Bursa of hand
Bursa of hand

Ulnar Bursa

It includes little finger tendon sheath

Begins at terminal phalanx and extends proximally halfway up to palm

Long FDS and FDP of fingers are excluded in common sheath while passing through the flexor retinaculum

Radial bursa communicates with Ulnar bursa at the carpal tunnel with each other in 80% of cases through Parona space

Hand Infections

Hand infections can involve any tissue type and a variety of pathogens

  • Staphylococcus aureus (most common)
  • Streptococcus (Second most common)

Risk factors

  • Antibiotics use in the previous year
  • Close and crowded living conditions
  • Compromised skin integrity
  • Sharing of items


Infections involving the nail fold are most common in the hand

Typically S. aureus

If this infection extends to eponychium= eponychia

If it involves both: Run-around infection

Nail anatomy
Nail anatomy


Incision/ drainage, partial or total nail plate removal, oral antibiotics, soaks, and dressing changes

Chronic paronychia is unresponsive to oral antibiotics therapy often secondary to fungal infections (Candida albicans)


Infection of the septated fingertip pulp

Deep space infection or abscess of the distal pulses pulp of finger or thumb

S. aureus


Incision and drainage through a central or mid-lateral incision

Septate must be broken up to adequately decompress the fingertip

Midlateral digital incisions are usually placed ulnarly, except in the thumb and small digit, where they are placed radially

The incision should be left open to heal by the second intension

Herpetic Whitlow

Caused by herpes simplex virus (HSV) type I

Dental hygienists, health care workers, and toddlers at risk

Intensely painful infection of the hand involving one or more fingers that typically affects the terminal phalanx

Formation of small vesicles that may coalesce into bullae

Diagnosis: Tzank smear and antibody titers

Self-limiting: Usually resolves within 7 – 10 days

Treatment with acyclovir may shorten the duration of symptoms

Web Space Infection

Collar button abscess/ Hourglass abscess

It is usually located in one of 3 fat-filled interdigital spaces just proximal to the superficial transverse ligament at the level of the MCP joint

If not drained may go towards mid-palmar space.

Drained by two longitudinal incisions one dorsally:- Between Metacarpal heads; One volar : Distal to the distal palmar crease and curving proximally

Deep Hand Infections

Cross section of hand
Cross section of hand
Dorsal subaponeurotic spaceDorsalExtensor tendons
VolarMetacarpals and interossei
Thenar spaceDorsalAdductor pollices
VolarIndex flexor tendons
RadialAdductor pollices insertion at P1 thumb
Mid palmar/ deepDorsalMiddle and ring finger metacarpals and 2/3 interossei
VolarFlexor tendons and lumbrical
UlnarHypothenar muscles
Hypothenar spaceRadialFibrous septum (Contains hypothenar muscles)
Posterior adductor spaceLocated dorsal to adductor pollices and palmer to 1st dorsal interossei

Mid-palmer space infections

Clinically rare

Loss of midline contour of the hand

Palmar pain elicited with flexion of the long, ring, and small fingers

Thenar and hypothenar space infections are rare

Manifested as pain and swelling over respective areas, exacerbated by flexion of the thumb or small fingers

Thumb abduction with painful adduction and opposition

Incision and drainage and IV antibiotics are required for all of these deep potential-space infections

Human bites

Potentially serious infections treated promptly with incision and drainage ( I and D), especially if joint or tendon sheath is violated

Most commonly involved the third or fourth MCP joint (fight bite)

Most frequently isolated organisms: group A streptococci, S. aureus, Eikenella corrodens, and Bacteroides spp.

Antibiotics for empiric therapy: IV ampicillin/sulbactam and oral amoxicillin//clavulanate

Dumbbell/ Pantaloon abscess: If involved in 1st web space

Pyogenic flexor tenosynovitis (FTS)

Infection of flexor sheath

It May occur in a delayed fashion after penetrating trauma

S.aureus is a common pathogen

Kanavel sign

  1. Flexed resting posture of digits
  2. Fusiform swelling of digits
  3. Tenderness of flexor tendon sheath
  4. Pain with passive digit extension

Early treatment: Hospital admission, splinting, IV antibiotics, and closed observation

If signs improve within the first 24 hours, surgery may be avoided

Late treatment: Incision and drainage of flexor tendons

Parona Space

Potential space in distal forearm located between:

Volar: Pronator quardatus

Dorsal: Digital flexor tendons

Ulnar: FCU

Radial: FPL

Can communicate between radial and ulna bursa

Infection: Horse shoe abscess

Classical horseshoe abscess: proximal communication between the thumb and small finger flexor tendon sheaths in the parona space (potential space between the PQ and FDP tendons)

To prevent tendon adhesion: aggressive hand physiotherapy is a must

Atypical nontuberculous mycobacterial infections

Most common organism: Mycobacterium marinum

Introduced by prick injuries from fish spines or hard fins in people working with fish or around fishing boats

Fishmonger’s infection: Chronic infection caused by M.marinum


Surgical debridement and oral antibiotics

See also: General Principles of Infections