Hand Infections

Most common organisms involved in hand infections

S. aureus or Streptococci

Why is early identification essential in hand infections?

Risk of damage to local structures and subsequent loss of function

Investigations for suspected hand infection?

Routine blood tests to aid diagnosis, including include CRP, WCC, and urate levels.+ Plain film radiographs+ wound swabs if producing pus to aid Abx choice

Why are plain film radiographs used in suspected hand infections?

As penetrating trauma is often a contributing factor in most hand infections, plain film radiographs are routinely used to exclude foreign bodies and assess for underlying fractures or evidence of osteomyelitis.

Management of suspected Hand infection

- Areas erythema marked to determine rate of spread - Abx

Paronychia

<ost common infection of the hand. Infection of the perionychium (the soft tissue fold around the nail plate) can occur secondary to contamination with oral flora from nail biting or sucking

Paronychia - risk factor

Previous trauma or injury causing a disruption to the perionychium can be a significant risk factor

Paronychia - pathophysiology / clinical features

Pus can track along the perionychium in a horse-shoe shape, producing a characteristic abscess at the skin-nail plate junction- fingertip may be swollen, inflamed, and very tender- pus can collect subungually, even cause necrosis of the nail bed and untreated paronychia can result in osteomyelitis of the distal phalanx

Paronychia - treatment

- Abx- Incision & drainage of pus - Nail plate removal MIGHT be necessary to allow sufficient pus drainage- Thorough washout normal saline + antiseptic

Infectious Tenosynovitis

inflammation of tendon sheath caused by infection

Infectious Tenosynovitis - cause (most common)

Direct inoculation of bacteria (commonly S. aureus) secondary to penetrating trauma

Tendosynovitis - most common type

Flexor sheath infections

Flexor sheath infections - emergency or not?

Surgical emergency: raised pressure within the tendon sheath can impair blood flow and lead to eventual tendon necrosis and rupture.

Tenosynovitis - features

Pain, swelling, and erythema of the affected digit

Strong indicator of flexor sheath infection

Kanavel's signs (4 cardinal features)

Kanavel's signs (4 cardinal features)

- Tenderness along the flexor sheath- Flexed finger posture- Pain on passive extension (early sign) - Fusiform swelling of the affected digit (sausage finger)

Tenosynovitis - management

Thorough washout of the flexor sheath in theatre followed by strict elevation and close monitoring

Felon Infections

Subcutaneous infection of the fingertip pulp, most commonly occur in the thumb or index finger and are caused by S. aureus.

Felon Infections - pathophysiology

Fibrous vertical septae run from the periosteum to the epidermis of the pulp, creating a closed system of microcompartments that are susceptible to rising pressure from inflammation

Felon Infections - features

Swelling of the pulp distal to the distal phalangeal crease and severe pain

Felon Infections - most common cause?

Direct contamination, e.g via splinters or garden thorns.

Felon Infections - management

- Simple, resolve spontaneously - Occasionally Abx may be required

Deep Hand Spaces

Thenar, mid-palmar, and hypothenar spaces.

Deep Hand Space Infections

Thenar, mid-palmar, and hypothenar spaces become swollen, tender, and erythematous, with hand movements limited.

Deep Hand Space Infections - Thenar space

Overlies adductor pollicis and is bound ulnarly by the insertion of the adductor onto the metacarpal; when infected, pus may track dorsally around the adductor and in-between its two heads

Deep Hand Space Infections - Mid Palmar space

Continuation of the carpal tunnel, deep to the palmar aponeurosis and superficial to the deep palmar interossei; it has multiple septa distally that separate the space and direct the flexor tendons to their digits

Deep Hand Space Infections - Hypothenar Space

Located palmar to the fifth metacarpal and dorsal to the hypothenar fascia

Differential Diagnosis hand infection

- Gout- Pseudogout- Cellulitis- Herpetic Whitlow- Pyoderma Gangrenosum- Retained foreign body

Complications of hand infections

- Tracking cellulitis- Subsequent sepsis - Damage to local structures