Emergent Care / Stabilization:

• Start (IV) intravenous therapy
• IV antibiotics
• Nothing by mouth

Causes / typical injury mechanism: Collar button infections are often caused by puncture wounds to palmar, thenar, or Parona space.

Classic history and presentation:

Deep space infection 

• The patient sustained a puncture wound (eg, gardening, animal bite, IV drug use) 24-72 hours prior to presentation.
• Presents with pain, tense fluctuance, increased pain with range of motion (ROM), and erythema surrounding the site.

Collar button abscess

• Deep space infection between 2 digits.
• Leads to an abducted position of the digits with associated swelling, erythema, and puckering of the adjacent skin.

Prevalence:

• 5%-15% of hand infections.

Risk factors:

• Puncture wound to the hand
• Immunosuppression; diabetes, HIV, autoimmune diseases

Pathophysiology: Compartmentalized by thick fascial septae, infections in the hand are trapped in expected areas. For example, an abscess in the hypothenar region cannot move radially toward the thumb due to the midpalmar septum. Rather, it travels along the flexor digiti minimi into the wrist where it travels through the Parona space, then to the flexor pollicis longus sheath and into the thenar space. This creates the classic "horseshoe abscess."

A collar button abscess originates in the volar webspace and is confined distally by the palmar aponeurosis. This causes the infection to spread dorsally into the subcutaneous tissues.

The most commonly isolated pathogens are Staphylococcus aureus and group A Streptococcus.