HAND INFECTIONS

8TH MAY 2016Mentor: Dr Dinesh

Presented by: R. Nandinii

OVERVIEW:◦Paronychia◦Felon◦Pyogenic flexor tenosynovitis◦Deep space infections◦Human bite◦Animal bite◦Take home messages

Anatomy

Paronychia◦Infection of the lateral nail fold◦If Infection extends to the

eponychium (defined as the thin membrane distal to the nail wall at the base of the nail), it is properly termed an eponychia. ◦When infection involves both

lateral nail folds and eponychium, it is called a run-around infection

◦In adults, Staphylococcus aureus is the most common pathogen

◦Pathophysiology ◦Infection occurs when there is violation of the seal between the nail

plate and nail fold, allowing the inoculation of bacteria.

◦Risk Factors◦Hangnails, ◦Manicures, ◦Penetrating trauma, ◦Constant exposure to a wet or moist environment, ◦Nail biting or sucking

Initial swelling, erythema, tenderness

with progression

to fluctuance, and abscess

formation are typical.

Spontaneous decompression can occur,

including tracking

beneath the nail plate

(subungual abscess).

Deeper infections can

involve the nailbed, pulp

space, and bone,

producing nailbed

destruction, felon, or

osteomyelitis

Clinical presentation

Treatment◦Early stage

◦Oral antibiotics,◦Warm soaks◦Rest and observation

◦Surgical decompression is the treatment of choice◦Decompression is performed by carefully entering the abscess cavity

between the nail plate and nail fold with a scalpel blade .

◦A small wick is placed for 24 to 48 hours to prevent the incision from closing and recurrence of the infection. The wick is removed, and saline warm soaks are begun

A: An infected lateral and proximal nail fold can be elevated by an elevator or scalpel. B: For extensive infections, a relief incision(s) is made perpendicular to the edge of the nail fold to allow for removal of a portion or all of the nail plate. (Reprinted from Seiler JG. Essentials of hand surgery . Philadelphia: Lippincott Williams & Wilkins, 2002, with permission. Copyright American Society of Surgery of the Hand.)

Depending on the extent of the infection, a partial or complete nail plate removal with or without lateral nail fold relief incision(s) is performed.

The incision should be made perpendicular to the edge of the nail fold.

A single or double incision is used depending on the location of the infection

Subungual abscesses are treated with removal of a portion of or the entire nail. The abscess is carefully debrided while protecting the sterile and germinal matrices

(A) Elevation of the eponychial fold with flat probe to expose the base of the nail. (B) Placement of an incision to drain the paronychium and to elevate the eponychial fold for excision of the proximal one-third of the nail. (C-E) Incisions and procedure for elevating the entire eponychial fold with excision of the proximal one-third of the nail. A gauze pack prevents premature closure of the cavity.

◦Chronic paronychia◦Chronic paronychia occurs more commonly in individuals constantly exposed to moist environments.

◦Infections may be intermittent; clinically, the eponichial fold is thickened and painful

◦Candida albicans is a frequent offending organism

◦Topical antifungal ointments are generally used 4 to 6 weeks.FIGURE 2. Eponychial marsupialization is performed by removing a small, crescent-

shaped portion of the eponychial fold proximal to the distal edge of the eponychial fold. Care is taken to not injure the underlying germinal matrix. (Reprinted from Seiler JG. Essentials of hand surgery . Philadelphia: Lippincott Williams & Wilkins, 2002, with permission. Copyright American Society of Surgery of the Hand.)

http://images.emedicinehealth.com/images/4453/4453-4482-13118-18394.jpg

Felon◦A felon is a deep space infection or abscess

of the distal pulp of the finger or thumb.

◦It differs from the superficial apical infection involving the distal portion of the pulp skin, which often responds to a small, deroofing incision

◦The organism most frequently cultured from a pulp space infection is S. Aureus

Felon Pathophysiology◦Infection typically is due to direct inoculation of

bacteria by penetrating trauma but may be caused by◦ hematogenous spread ◦ local spread from an untreated paronychia.

◦Most common in thumb and index finger.

Clinical presentation◦Throbbing pain and◦Tense swelling localized to the pulp

Felon“Don’t wait for fluctuation if tension is

severe”◦Infection results in edema increased pressure within the closed

compartment impaired venous outflow local compartment syndrome

◦Untreated felons can: extend toward the phalanx --> osteomyelitis toward the skin --> draining sinus obliterate vessels ---> skin slough or necrosis suppurative flexor tenosynovitis or septic arthritis of the DIPJ

Treatment If recognized early (mild cellulitis): soaks & AbxLater (abscess formation): surgical drainage

Usually process has been going on > 48 hrs.

Principles:Avoid injury to nerve and vessel structuresUtilize an incision that won’t leave a disabling scarDo not violate flexor sheath (stay distal)Produce adequate drainage

• The best is a longitudinal incision over the area of greatest fluctuance because it avoids– Skin slough– Digital nerve injury – Creation of an unstable fat pad

• To avoid penetration of the tendon sheath, the incision should not extend to the distal interphalangeal crease. Incise on lateral aspect of digit 5mm

dorsal & distal to the DIP flexion crease Continue distally to a point 5mm away

from the edge of the free nail Deepen the incision with a clamp within a

plane just volar to the palmar cortex of the DPLocation of Incisions:

Index, middle & ring: ULNAR SIDEThumb & small: RADIAL SIDE

Additional measures◦Pus should be taken for C&S

◦Initial empiric antibiotic coverage with a second-generation cephalosporin, such as cefazolin, while awaiting culture identification and sensitivity is usually adequate.

◦Addition of gram-negative coverage is recommended in an immunocompromised individual.

◦Postoperative wound care, edema control, splinting, and motion optimization are preferably pursued with therapy supervision

Pyogenic flexor tenosynovitisAnatomy

Flexor sheaths are closed spaces Extend from the mid-palmar crease

to the DIPJ (Prox edge of A1 pulley to distal edge of A5 pulley)

Flexor sheath of small finger is continuous proximally with the Ulnar Bursa, while the sheath of the thumb is continuous with the Radial Bursa

Radial & Ulnar bursae extend proximal to the TCL and connect with the Parona space(Potential space between FDP & PQ muscle)

Flexor sheath infections most often as a result of penetrating trauma More likely at joint flexion creases Sheaths are separated from skin by only a small amount of

subcutaneous tissue here Also, Felons can rupture into the distal flexor sheath Usual causative agent: S. Aureus Most commonly affected digits:

Ring, long & index fingersPurulence within the sheath destroys the gliding mechanism, rapidly creating adhesions that lead to loss of function

Destroys the blood supply producing tendon necrosis

ClinicalKanavel’s 4 cardinal signs:

Tenderness over & limited to the flexor sheath Symmetrical enlargement of the digit (“fusiform”) Severe pain on passive extension of the finger (>

proximally) Flexed posture of the involved digit

Not all four signs may be present early onMost reliable sign: pain w. passive extension

Cellulitis of the hand may appear similar, but swelling & tenderness is not usually isolated to a single digit

Treatment

Early infection < 48 hrs (& usually lacking all 4 signs) may initially be treated with IV Abx, splinting & elevationFailure to respond within 24 hrs. should necessitate drainage

Established pyogenic tenosynovitis is a surgical emergencyRequires prompt surgical drainageDelays may result in tendon &/or skin necrosis

Treatment2 basic approaches:

Open vs. Closed

Open drainage:Decompression of the entire tendon sheath via mid-axial & palmar incisions

Wounds are left open to drain & heal secondarily

Rehab is prolonged; permanent finger stiffness not infrequent

Most useful for advanced cases where resection of necrotic tendon is required

Treatment

Closed tendon-sheath irrigation: 2 incisions made Proximal palm: open the sheath proximal to the A1 pulley Distal mid-axial: open sheath distal to the A4 pulley

Long irrigation catheter (16 - 18g) is placed in the proximal sheath with a drain left in the distal incision

Incisions are then closed, and sheath is irrigated for 48 - 72 hrs.

May use NS or Abx solution (continuous drip or q2h flush) Addition of marcaine alleviates pain of irrigation

Modification involves multiple transverse incisions of cruciate pulleys with insertion of silastic drains

Chronic TenosynovitisUnusual cases may be seen which present differently than acute pyogenic infections: Chronic swelling of the flexor sheath No disabling pain or loss of function

These are chronic infections most frequently caused by mycobacteria usually the result of a puncture wound in an aquatic environment M. Kansasii or M. Marinarum

Dx: AFB stains & culture of synoviumTx: tenosynovectomy + antituberculous drugs (6 - 24 mo)

Deep Space Infections4 deep spaces clinically significant in hand infections:

Subfascial palmar spaceDorsal subaponeurotic spaceThenar spaceMidpalmar space

Deep Space InfectionsSubfascial Palmar Space Infections subfascial palmar space communicates with the dorsal

subcutaneous space via web spaces between the digits usually spread dorsally (“collar button abscess”)

Double abscess: +/- palmar & dorsal abscesses connected through hole in fascia

Palmar spread is limited by the relationship of fascia to skin

Causes: Fissure in the skin between the fingers Distal palmar callus (MC head) Extension from subcutaneous infection in proximal

finger Severe distal palmar swelling with an abducted finger

Puss-filled web spaces

Subfascial Palmar Space InfectionsTreatment

2 important points:Do not incise web space transversely

Be alert for the double abscess configuration

Drainage is via a palmar approach with division of the palmar fascia to expose both the volar & dorsal compartments

Deep Space InfectionsDorsal Subaponeurotic Space Infections

DSS is beneath the extensor tendons on the dorsum of the hand

Often the result of penetrating trauma neglected human bites

Dorsal swelling, erythema & tenderness + history make the diagnosis

Drain via linear incisions over the 2nd & 4th MC’s while preserving soft tissue coverage over the tendons occasionally direct incision over a pointing

abscess is necessary Risks exposure (desiccation) of extensor

tendons

Deep Space InfectionsThenar Space Infections Thenar space follows the direction of Adductor Pollicis:

Dorsal: AP muscle

Volar: index flexor & 1st lumbrical

Radial: insertion of AP (proximal phalanx of the thumb)

Ulnar: oblique septum from skin to the 3rd MC

Thenar Space InfectionsClinical Causes:

penetrating injury thumb or index subcutaneous abscess thumb or index flexor tenosynovitis extension from radial bursa or

midpalmar space marked swelling of the thenar

eminence & 1st web space thumb forced into abduction severe pain with extention or opposition infection tracks dorsally via 1st web space,

over the AP & 1st dorsal interosseous muscles.

Thenar Space InfectionsTreatment Drain via volar or dorsal incisions

in the 1st web space or both: Identify neurovascular structures unroof the adductor fascia to open

the abscess cavity irrigate & debride catheter in volar incision & close;

penrose in dorsal incision & close compressive dressing & plaster splint

Deep Space InfectionsMidpalmar Space Infections Boundaries:

Dorsal: intrinsic muscles Volar: flexor tendons Radial: oblique septum from

the skin to the 3rd MC Ulnar: hypothenar muscles Distal: vertical septa of palmar fascia Prox: fascial layer at distal carpal tunnel

Deep Space InfectionsMidpalmar Space Infections Clinical:

usually due to direct penetrating trauma, rupture of tenosynovitis

loss of palmar concavity, dorsal swelling, tenderness volarly

Midpalmar Space InfectionsTreatment Drain via wide palmar incisions

with +/- resection of palmar fascia to ensure drainage of abscess cavity.

or may place irrigation catheter & drain and close primarily.

Bursal Infections Usually due to spread of flexor

tenosynovitis from thumb or small finger

Radial bursa: Proximal extension of

tendon sheath of FPL extends through the carpal

tunnel into the distal forearm

Ulnar bursa: Proximal extension of tendon

sheath of FDP of small finger

Bursal InfectionsTreatmentClosed irrigation using 2 incisions, a catheter & a drain as previously outlined.

Human BitesOften undertreated & misdiagnosed leading to significant morbidity

The most serious form of human bite infection is the clenched fist injury:

Any laceration over the head of a metacarpal is a human bite injury until proven otherwise

Human BitesThe wound that results from a punch to the mouth may appear insignificant and treatment may not be sought for days.

It often results in immediate inoculation of the subcutaneous tissue, the subtendinous space and the MCP joint with saliva Human saliva may contain over 108 microorganisms per ml. Over 42 species of bacteria identified Thus: Polymicrobial infection is the rule

Common organisms: S. Aureus, Strep sp., Eikenella: gram neg facultative anaerobe in ~ 30% (incr. severity)

Human BitesDelay in onset of treatment is directly proportional to poor outcomes: In general, human bites treated within 24 hrs. rarely have serious

complications

in E.D.: Debride, irrigate, pack open Abx to cover gram +’s & eikenella (Pen & Ceph) +/- admission to follow response

To O.R.: Established joint space penetration, & more severe infections

Animal BitesDog more common than cat (5%)

Cat bites are particularly virulent & can result in deep puncture wounds that are hard to clean

More than half involve kidsBasic principles of debridement & irrigation apply

Deep puncture wounds are left open & may require extension Established infections are debrided & packed open Superficial lacerations may be loosely closed after irrigation

Common organisms: S. Aureus, Strep viridans, Pasturella (#1 in cats), anaerobes

Abx: ampicillin (Clavulin on outpatient basis)

Take home messages:Not all hand

swellings are

cellulitis

PFT is a surgical

emergency

Remember 4

Kanavel’s sign

If swelling doesn’t

subside in 24h…I&D

Most common organism

Staph Aureus

THE END