Web Space Infections

Tiffany J. Pan

John R. Fowler

INTRODUCTION

Definition
- A deep infection of the hand that occurs in the webspace between two fingers
- It is also known as a collar-button abscess in reference to the dumbbell shape reminiscent of collar buttons from the early 20th century
Pathoanatomy
- Deep subfascial spaces
  - Dorsal subcutaneous space
  - Dorsal subaponeurotic space
    - Dorsal limit—dense aponeurosis of extensor tendons
    - Volar limit—metacarpal periosteum and dorsal fascia of interossei muscles
    - Medial and lateral borders—confluence of aponeurotic sheet and deep fascia over dorsal interossei as well as metacarpal bones and metacarpophalangeal joint capsules
  - Interdigital webspace
    - Loose connective tissue between the metacarpal heads
    - Skin is intimately attached to the palmar fascia volarly but is relatively mobile dorsally
- Dorsal spread is most common due to the dense attachment of the volar skin to the palmar fascia limiting formation of the abscess
- Infections are able to track through the loosely organized tissue of the interdigital webspace
Mechanism of injury
- Superficial skin fissure in the webspace
- Palmar callus
- Penetrating injury, frequently of the volar surface
- Attempted injection of IV drugs
- Extension of infection from adjacent fingers
Epidemiology
- 5% to 15% of hand infections are deep space infections
- Staphylococcus aureus and group A beta-hemolytic Streptococcus are the most common organisms identified
- Human bites likely to cause polymicrobial infection