Plastics - infections

Question 1

Skin abcess

Answer 1

https://teachmesurgery.com/plastic-surgery/infections/skin-abscess/

Question 2

Hidradenitis Suppurativa

Answer 2

https://teachmesurgery.com/plastic-surgery/infections/skin-abscess/

Question 3

Bite injuries

Answer 3

https://teachmesurgery.com/plastic-surgery/infections/bite-injuries/

Question 4

Hand infections

Answer 4

https://teachmesurgery.com/plastic-surgery/infections/hand-infections/

Question 5

Paronychia

Answer 5

Paronychia is the most 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. Previous trauma or injury causing a disruption to the perionychium can be a significant risk factor.

Pus can track along the perionychium in a horse-shoe shape, producing a characteristic abscess at the skin-nail plate junction*. The fingertip may be swollen, inflamed, and very tender (Fig. 2); pus can collect subungually, even cause necrosis of the nail bed and untreated paronychia can result in osteomyelitis of the distal phalanx.

Treatment typically involves antibiotics, however incision and drainage of the pus will be required. Nail plate removal may be necessary to allow for sufficient drainage of pus. Following incision and drainage, a thorough washout with normal saline and antiseptic solution is necessary, with regular dressing changes.

Question 6

Infectious tenosynovitis

Answer 6

Tenosynovitis is inflammation of tendon sheath, the most common cause of which is infection. Tenosynovitis most often arises from direct inoculation of bacteria (commonly S. aureus) secondary to penetrating trauma*

The most common type of tendosynovitis are flexor sheath infections. These should be deemed as a surgical emergency, as the raised pressure that occurs within the tendon sheath can impair blood flow and lead to eventual tendon necrosis and rupture.

*Haematogenous spread or direct spread from a felon, septic joint or deep space infection can also lead to infectious tenosynovitis

Patients present with pain, swelling, and erythema of the affected digit. Kanavel’s signs (4 cardinal features, Fig. 4) are strong indicators of flexor sheath infection:

Tenderness along the flexor sheath
Flexed finger posture
Pain on passive extension
Fusiform swelling of the affected digit
A thorough washout of the flexor sheath in theatre followed by strict elevation and close monitoring should be the mainstay of treatment. It is common practice to perform a re-look and further washout in theatre, especially if the clinical features do not resolve.

Question 7

Felon Infections

Answer 7

A felon infection is a subcutaneous infection of the fingertip pulp, most commonly occur in the thumb or index finger and are caused by S. aureus.

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 present with swelling of the pulp distal to the distal phalangeal crease and severe pain (Fig. 5). The most common cause is through direct contamination, such as via splinters or garden thorns.

Most cases are simple and will resolve spontaneously after a short period; antibiotics can aid resolution.

Question 8

Deep hand space infections

Answer 8

The deep spaces of the hand consist of the thenar, mid-palmar, and hypothenar spaces. When infected, the respective spaced become swollen, tender, and erythematous, with hand movements limited.

The 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
The mid-palmar space is a 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
The hypothenar space is located palmar to the fifth metacarpal and dorsal to the hypothenar fascia

Question 9

Differentials for worsening hand swelling and pain

Answer 9

gout* and pseudogout, cellulitis, herpetic whitlow, pyoderma gangrenosum, or retained foreign body.

Paronychia, infectious tenosynovitis, felon infections, deep hand space infections

Question 10

Complications of hand infections

Answer 10

Tracking cellulitis
Subsequent sepsis
Damage to local structures - tendons, joints

Question 11

Necrotising fascitis

Answer 11

https://teachmesurgery.com/plastic-surgery/infections/necrotising-fasciitis/