01Approach to the Critical Patient/attcp64

Immediate recognition and escalation

›Time-sensitive recognition triggers

›All 4 Kanavel signs present — emergent hand surgery activation

›Do not delay surgical consultation for imaging

›Outcome directly tied to time-to-drainage

›Rapid proximal spread of erythema or swelling into palm or wrist

›Bursal involvement suspected

›Horseshoe abscess risk

›Systemic toxicity

›Fever, tachycardia, hypotension

›Sepsis criteria met

›Skin necrosis, crepitus, or subcutaneous purulence

›Pang classification Stage III

›Worst prognosis — emergent OR

›Immediate stabilization steps

›Hand elevation above level of heart

›Reduces edema and pressure within tendon sheath

›Initiate immediately on arrival

›IV access and fluid resuscitation if septic

›Target MAP >= 65 mmHg

›Lactate-guided resuscitation

›Splint in position of function

›Wrist 20 to 30 degrees extension

›MCP 70 to 90 degrees flexion

›IP joints in slight flexion

›Tetanus prophylaxis assessment

›Verify immunization status

›Administer if not current

02History/hx64

Mechanism and onset

›Penetrating trauma to volar digit

›Puncture wounds most common mechanism

›Splinters, thorns, needles

›Fingerstick glucose testing reported cause

›Lacerations to volar surface

›Animal or human bites

›Pasteurella multocida in dog and cat bites

›Polymicrobial in human bites

›No clear trauma history in approximately 30% of cases

›Hematogenous seeding

›Occult inoculation

›Symptom timeline

›Onset typically 24 to 72 hours after inoculation

›Indolent organisms may delay presentation

›Mycobacterium marinum causes subacute course

›Rapid progression of pain, swelling, and stiffness

›Inability to flex or extend digit

›Symptoms worsening over hours

Symptom characterization

›Cardinal local symptoms

›Pain along volar aspect of finger

›Worsened by any passive motion

›Often severe and disproportionate

›Diffuse swelling of the entire digit

›Fusiform or sausage-shaped appearance

›Rigid posture with digit held partially flexed

›Systemic symptoms

03Physical Exam/exam60

Kanavel cardinal signs

›Four classic signs (Kanavel 1912)

›Fusiform symmetric swelling of entire digit

›Diffuse not focal

›Extends from base to tip of finger

›Flexed posture of digit at rest

›Resting semiflexed position to reduce sheath pressure

›Pain with passive extension

›Most sensitive individual sign

›Stretches inflamed sheath

›Tenderness along flexor tendon sheath

›Volar midline tenderness proximal to distal

›Point tenderness at A1 pulley

›Sign interpretation

›All 4 signs present has high specificity for PFT

›Not all signs always present — only 34% of pediatric cases had all 4

›Pain with passive extension most reliable single sign

›Kanavel signs in aggregate are the primary differentiating tool

Proximal spread and complications

›Palmar and wrist assessment

›Palmar tenderness

›Thenar or hypothenar space involvement

›Suggests bursal spread

›Wrist swelling

›Radial or ulnar bursal extension

›Space of Parona involvement (horseshoe abscess risk)

›Forearm swelling or tenderness

›Proximal bursal extension

04Differential Diagnosis/ddx49

Life-threatening and urgent diagnoses

›Necrotizing fasciitis of the hand

›ICD-10 M72.6

›Rapid soft tissue destruction

›Crepitus and skin necrosis

›Requires emergent surgical debridement

›Mortality without surgery

›Septic arthritis of finger joints

›ICD-10 M00.04 (DIP), M00.041 (PIP)

›Joint-line tenderness and warmth

›Pain with axial loading of digit

›Differentiating clue: tenderness localized to joint not entire sheath

›Horseshoe abscess

›Thumb or small finger PFT extending through space of Parona

›Bilateral thenar and hypothenar swelling

›Acute carpal tunnel syndrome possible

›Requires simultaneous bilateral bursal decompression

Common local mimics

›Felon (pulp space abscess)

›ICD-10 L02.01

›Pain and swelling isolated to fingertip pulp

›No proximal tenderness along tendon sheath

›Differentiating clue: confined to distal compartment

›Cellulitis or subcutaneous abscess

›ICD-10 L03.01

›Diffuse erythema without Kanavel signs

›No fusiform swelling or passive extension pain

›Pearl: CRP and WBC may actually be higher in cellulitis than early PFT

05Laboratory Tests/lt49

Core infection and metabolic labs

›Complete blood count with differential

›Leukocytosis supports infection but may be absent in early PFT

›WBC is neither sensitive nor specific for PFT diagnosis

›Left shift supports bacterial infection

›Leukopenia as severe sepsis or immunosuppression marker

›Inflammatory markers

›C-reactive protein

›Often normal in early PFT

›May be more elevated in cellulitis than early PFT

›Serial trending more useful than single value

›ESR

›Nonspecific systemic inflammation marker

›Baseline value for monitoring

›Basic metabolic panel

›Renal function

›Creatinine for vancomycin dosing

›Electrolytes for resuscitation planning

›Blood glucose and HbA1c

›Screen for undiagnosed diabetes

›Hyperglycemia associated with worse outcomes

Microbiology

›Blood cultures

›Indicated when systemic sepsis signs present

›Fever, tachycardia, or hypotension

›IVDU patients with bacteremia risk

›Obtain before antibiotics when feasible

›Two sets from separate sites

06Diagnostic Tests/dt92

Scoring Systems

›Kanavel sign count as clinical staging

›1 to 2 signs present

›Early or equivocal disease

›Consider antibiotic trial with close monitoring

›3 to 4 signs present

›Established PFT — surgical drainage indicated

›Time-to-OR correlates with outcomes

›Clinical note: no validated numeric scoring system exists; Kanavel count is pragmatic staging

›Pang classification for disease severity

›Stage I: purulent fluid in sheath

›Acute suppurative phase

›Amenable to closed catheter irrigation

›Stage II: granulation tissue with cloudy fluid

›Subacute or undertreated disease

›Open irrigation often preferred

›Stage III: necrosis of tendon sheath

›Worst prognosis

›Requires open debridement and possible tendon reconstruction

›Risk stratification note

›Diabetes, PVD, and immunosuppression predict worse outcomes

›Amputation risk increased with comorbidities

›ACEP Level C: individualize management based on host factors

MRI

›MRI hand indications

›Equivocal diagnosis when clinical exam unclear

›Not routinely required for clinical diagnosis

›May delineate extent of sheath involvement

›Complex or atypical presentations

›Suspected deep space extension

›Subacute course suggesting atypical organism

›Post-operative complication evaluation

›Suspected osteomyelitis after treatment failure

›Tendon integrity assessment

›MRI findings in PFT

›Fluid within tendon sheath on T2 sequences

›High signal surrounding flexor tendon

›Sheath distension

›Tenosynovial enhancement with gadolinium

›Indicates active inflammation or synovitis

›Bony signal changes

›Osteomyelitis complication

›Marrow edema pattern

›Practical limitations

›Availability and time constraints

›Should not delay emergent surgery

›Most useful for stable, diagnostically uncertain cases

›Non-compatible implants contraindication

›Screen for metallic foreign bodies in trauma mechanism

CT

›CT hand indications

›Foreign body detection

›Radiopaque foreign body not visible on plain film

›Glass, metal fragments

›Deep space abscess evaluation

›Midpalmar or thenar space involvement

›Horseshoe abscess delineation

›Suspected gas-forming infection

›Necrotizing fasciitis differential

›Crepitus on exam

›CT findings relevant to PFT

›Fluid collection within tendon sheath

›Low density fluid surrounding tendon

›Sheath wall thickening

›Soft tissue gas

›Necrotizing infection indicator

›Emergent surgical finding

›Bony erosion

›Osteomyelitis complication

›Radiology guidance note

›CT not required for straightforward PFT diagnosis

›PFT remains a clinical diagnosis

›CT for surgical planning in complex cases

Ultrasound

›Point-of-care ultrasound (POCUS) for PFT

›Sheath fluid detection

›Anechoic or complex fluid surrounding flexor tendon

›Linear high-frequency probe (15 to 18 MHz)

›Hyperemia on Doppler

›Increased peritendinous flow

›Active inflammatory process

›Tendon integrity

›Disruption or necrosis in advanced disease

›Diagnostic performance

›Fluid in sheath supportive but not diagnostic

›Small amounts of physiologic fluid can be normal

›Complex fluid more specific for infection

›Not required to make the diagnosis

›PFT is a clinical diagnosis based on Kanavel signs

›Do not delay surgical consultation for ultrasound

›Ultrasound-guided aspiration

›Needle aspiration of sheath fluid for Gram stain and culture

›Can be performed in ED under ultrasound guidance

›Purulence or positive Gram stain confirms diagnosis

›Therapeutic role limited without formal drainage

›Not a substitute for surgical irrigation

07Disposition/dispo48

Admission and surgical consultation

›Admission indications

›All patients with clinical diagnosis of PFT require admission

›IV antibiotics and surgical evaluation mandatory

›ACEP Level C recommendation

›Emergent hand surgery consultation for all cases

›Time-to-drainage directly impacts outcomes

›Most cases beyond earliest presentation require OR

›Average hospitalization approximately 5 days

›Longer with comorbidities or complications

›ICU admission triggers

›Septic shock

›Vasopressor requirement

›Persistent MAP < 65 mmHg

›Necrotizing soft tissue infection

›Emergent OR from ED

›ICU post-operatively

›Bacteremia with end-organ involvement

›S. aureus bacteremia with endocarditis concern

›IVDU patient with septic emboli risk

Specialty consultations

›Hand surgery

›All cases — emergent consultation

›Do not defer for imaging if clinical diagnosis established

›Repeat I&D in 18% of cases

›Monitor for treatment failure

›Infectious disease

›MRSA bacteremia

08Treatment/t102

Initial ED management

›Non-pharmacologic immediate measures

›Hand elevation

›Above level of heart continuously

›Bulky soft dressing

›Splinting in position of function

›Wrist 20 to 30 degrees extension

›MCP 70 to 90 degrees flexion

›IP joints neutral to slight flexion

›IV access

›Two large bore peripheral IVs for septic patients

›Fluid resuscitation if hemodynamically compromised

›Tetanus prophylaxis

›Td booster if last dose over 5 years ago

›TIG if unimmunized and contaminated wound

Empiric antibiotic therapy

›First-line empiric regimen (standard host)

›Vancomycin IV (MRSA coverage)

›15 to 20 mg/kg IV every 8 to 12 hours

›Adjusted for renal function

›AUC-guided monitoring preferred

›Target AUC/MIC 400 to 600

›Plus broad-spectrum gram-negative coverage

›Ceftriaxone 1 to 2 g IV every 24 hours

›Or piperacillin-tazobactam 3.375 g IV every 6 hours for severe illness

›Start immediately — do not delay for imaging or cultures

›Early antibiotics most closely correlated with good outcomes

›ACEP Level C recommendation

›Animal bite regimen

›Ampicillin-sulbactam 3 g IV every 6 hours

›Covers Pasteurella multocida

›Covers oral anaerobes and streptococci

›Or piperacillin-tazobactam 3.375 g IV every 6 hours

›Broader gram-negative coverage

›Preferred for severe presentations

›Renal adjustment required for both agents

›Aquatic exposure regimen

›Add coverage for Mycobacterium marinum

›Clarithromycin 500 mg IV or PO every 12 hours

›Or azithromycin 500 mg IV or PO daily

›Consider Shewanella and Vibrio coverage

›Ciprofloxacin 400 mg IV every 12 hours

›Extended gram-negative spectrum

›Infectious disease consultation strongly recommended

Surgical management

›Surgical approach options

›Closed catheter irrigation (two-incision technique)

›Preferred for Pang Stage I (early disease)

›Proximal and distal incisions with indwelling catheter

›Continuous or intermittent irrigation

›May yield better range-of-motion outcomes

›Open irrigation and debridement

›Pang Stage II or III disease

›Mid-lateral incision along digit

›Direct visualization of tendon and sheath

›Limited incision I&D

›Most commonly performed approach

›18% of cases require repeat I&D

›Post-operative antibiotics

›Culture-guided de-escalation when sensitivities return

›Narrow to targeted spectrum

›Avoid prolonged broad-spectrum without indication

›Typical total course 1 to 2 weeks

›IV to PO transition when clinically improving

›Oral options based on organism and sensitivities

›Post-operative care

›Early active mobilization

›Hand therapy initiated as soon as feasible

›Reduces contracture and stiffness

›Wound care and dressing changes

›Monitored by hand surgery and nursing

›Elevation continued post-operatively

Antibiotic de-escalation and oral transition

›Oral antibiotic options on clinical improvement

›Trimethoprim-sulfamethoxazole (MRSA coverage)

›1 to 2 DS tablets PO every 12 hours

›When culture confirms MSSA or MRSA susceptibility

›Dicloxacillin (MSSA)

›500 mg PO every 6 hours

›Take on empty stomach for absorption

›Cephalexin (MSSA, streptococcal coverage)

›500 mg PO every 6 hours

›Amoxicillin-clavulanate (bite wounds)

›875 mg PO every 12 hours

›Covers Pasteurella and oral flora

›Transition criteria

›Afebrile for 24 to 48 hours

›Tolerating oral intake

›Decreasing edema and erythema

›No signs of systemic infection

›Normalizing WBC trend

›Hand therapy progressing

Adjunct therapies

›Pain management

›Acetaminophen 650 to 1000 mg PO or IV every 6 to 8 hours

›Scheduled dosing preferred

›Ibuprofen 400 to 600 mg PO every 6 to 8 hours with food

›If renal function adequate

›Opioid analgesics for severe pain

›Short course only

›Lowest effective dose

›Glycemic control

›Tight glucose management in diabetic patients

›Hyperglycemia impairs immune function

›Target glucose 7.8 to 10 mmol/l in hospitalized patients

›Insulin therapy as indicated

›Endocrine consultation for complex diabetes

09Special Populations/sp87

Pregnancy

›Physiologic considerations

›Immune modulation in pregnancy

›Altered inflammatory response may attenuate signs

›PFT not inherently more common in pregnancy

›Hand edema is common in pregnancy

›May mask or confound Kanavel sign assessment

›Maintain high clinical suspicion

›Antibiotic selection in pregnancy

›Vancomycin

›Considered when MRSA coverage required

›Monitor renal function closely — placental transfer occurs

›Beta-lactams generally preferred

›Ampicillin-sulbactam acceptable in pregnancy

›Cephalexin for oral step-down

›Avoid fluoroquinolones

›Teratogenic risk (cartilage effects in animal studies)

›Use only when benefit clearly outweighs risk

›Avoid tetracyclines

›Dental and bone effects in fetus

›Surgical management in pregnancy

›Emergent surgical drainage not contraindicated

›General vs regional anesthesia discussion with OB

›Fetal monitoring perioperatively if viable gestation

›Delay does not improve fetal outcomes

›Untreated sepsis poses greater risk to fetus than surgery

›Fetal monitoring

›Viable gestation: continuous fetal monitoring during procedure

›Neonatology notification if preterm gestation

›Maternal SpO2 maintained >= 95%

Geriatric

›Atypical presentation in older adults

›Attenuated fever and inflammatory response

›Afebrile infection common

›Normal WBC does not exclude PFT

›Reduced pain perception

›Less dramatic pain with passive extension

›May present later in disease course

›Delirium as presenting symptom of systemic infection

›Confusion in absence of classic hand findings

›Comorbidity burden

›Diabetes and PVD prevalent

›Highest risk for amputation and poor outcomes

›Aggressive early surgical management preferred

›Polypharmacy and drug interactions

›Vancomycin nephrotoxicity risk increased with baseline CKD

›AUC-guided dosing particularly important

›Anticoagulation

›Increased intraoperative bleeding risk

›Reversal planning with hand surgery

›Functional outcomes

›Baseline hand function documentation important

›Pre-existing arthritis or contracture

›Prolonged hand therapy requirements

›Rehabilitation access in elderly patients

›Goal of care discussion when frailty is severe

Pediatrics

›Epidemiology in children

›PFT less common in pediatric population

›Accounts for minority of pediatric hand infections

›Only 34% of pediatric cases present with all 4 Kanavel signs

›Diagnosis may be more challenging

›Maintain high suspicion with partial Kanavel signs

›Hematogenous seeding relatively more common than in adults

›Causative organisms in children

›S. aureus most common across all ages

›MRSA prevalence similar to adults

›Unusual organisms in immunocompromised children

›Fungal tenosynovitis rare

›Antibiotic dosing (weight-based)

›Vancomycin IV

›15 mg/kg per dose IV every 6 to 8 hours

›AUC-guided monitoring preferred

›Ampicillin-sulbactam IV

›50 mg/kg per dose of ampicillin component IV every 6 hours

›Maximum adult dose

›Cephalexin PO (oral step-down)

›25 to 50 mg/kg per day divided every 6 hours

›Maximum 4 g per day

›Surgical considerations in children

›General anesthesia required

›Age-appropriate consent and assent

›Pediatric anesthesia team involvement

›Post-operative rehabilitation

›Pediatric occupational therapy

›Play-based therapy for younger children

›Child protection

›Recurrent or unexplained hand infections

›Consider neglect or non-accidental injury

›Safety planning and referral as indicated

10Background/b88

Epidemiology

›Incidence and burden

›PFT comprises 2.5 to 9.4% of all primary hand infections

›Uncommon but high-morbidity condition

›Reported across all age groups

›Mean age of presentation in fourth to fifth decade

›Male predominance in most series

›Geographic and occupational clustering

›Higher incidence in manual workers

›Fishermen, butchers, gardeners at elevated risk

›Causative organisms

›S. aureus most common (including MRSA)

›MRSA frequency varies by community prevalence

›CA-MRSA increasingly common cause

›Streptococcus species

›Group A Streptococcus can cause aggressive disease

›Gram-negative organisms

›Pasteurella multocida in bite wounds

›Eikenella corrodens in human bites

›Pseudomonas in immunocompromised or IVDU

›Polymicrobial infection in approximately 19% of cases

›Atypical organisms in special exposures

›Mycobacterium marinum (aquatic)

›Shewanella algae (saltwater)

›Candida species in immunocompromised

›Outcomes data

›Residual digital stiffness expected even with optimal treatment

›Most common long-term sequela

›Full ROM recovery may take weeks to months

›Amputation rate higher with diabetes and PVD

›Delay to surgery increases complication risk

›Mortality rare but reported in septic patients

Pathophysiology

›Anatomic basis of infection

›Flexor tendon sheath anatomy

›Closed synovial space surrounding flexor digitorum superficialis and profundus tendons

›Extends from A1 pulley at MCP joint to distal insertion

›Low-oxygen, low-flow environment favors bacterial growth

›Bursal communication

›Thumb flexor sheath communicates with radial bursa

›Small finger flexor sheath communicates with ulnar bursa

›Radial and ulnar bursae communicate through space of Parona

›Anatomic basis for horseshoe abscess formation

›Annular pulley system

›A1, A2, A3, A4, A5 pulleys restrict tendon bowstringing

›Constrain infection spread and increase sheath pressure

›Infectious process

›Inoculation via penetrating trauma

›Direct implantation of organisms into sheath

›Less commonly hematogenous seeding

›Bacterial proliferation in avascular sheath fluid

›Rapid bacterial replication in closed space

›Rising sheath pressure compromises tendon blood supply

›Tendon ischemia and necrosis

›Vincular blood supply compressed by sheath hypertension

›Tendon necrosis if decompression delayed

›Pang staging reflects progressive tissue destruction

›Stage I: purulent fluid, viable tendon

›Stage II: granulation tissue, still viable

›Stage III: necrosis of tendon sheath and potentially tendon

Therapeutic Considerations

›Antibiotic principles

›MRSA empiric coverage is standard of care

›Vancomycin remains first-line for MRSA

›Daptomycin alternative when vancomycin intolerant

›Culture-guided de-escalation reduces resistance pressure

›Intraoperative cultures essential

›Narrow within 48 to 72 hours of culture results

›Duration typically 1 to 2 weeks total

›Culture-guided adjustment

›Longer for atypical organisms (Mycobacterium marinum)

›Surgical principles

›Early drainage is the cornerstone of treatment

›IDSA guideline supports prompt surgical drainage

›Time from symptom onset to surgery affects outcomes

›Closed catheter irrigation may preserve ROM better

›Evidence from comparative case series

›Requires catheter maintenance post-operatively

›Open debridement for advanced disease

›Pang Stage II to III has worse prognosis regardless of technique

›Hand therapy as integral part of treatment

›Early active mobilization reduces stiffness

›Referral within 1 week of surgery

›Evidence base summary

›No randomized controlled trials exist for PFT management

›Evidence from retrospective case series and systematic reviews

›Giladi 2015 systematic review in J Hand Surg Eur

›Forder 2024 systematic review JPRAS

›IDSA 2014 skin and soft tissue infection guidelines include PFT

›Stevens DL et al, CID 2014

›Anderson 2026 JBJS Reviews — updated management review

11Patient Discharge Instructions/pdi33

copy discharge instructions

›Flexor tenosynovitis hand infection home care

›Take all antibiotics exactly as prescribed

›Complete the full course even if feeling better

›Do not skip doses

›Keep the hand elevated above heart level as much as possible

›Reduces swelling and pain

›Use pillows or a sling

›Attend all hand therapy appointments

›Critical to regain finger movement

›Start as soon as surgeon recommends

›Wound care as instructed by your surgeon

›Keep dressing clean and dry

›Do not remove or change dressing unless instructed

›Expected recovery course

›Some stiffness in the finger is expected even with good treatment

›Full recovery of movement may take weeks to months

›Hand therapy significantly improves outcomes

›Swelling and soreness improve gradually

›Report any worsening to your surgeon

›Patients with diabetes or poor circulation take longer to heal

›Tighter sugar control helps recovery

›Warning signs to return to ER immediately

›Worsening pain, redness, or swelling in the finger or hand

›Fever greater than 38.5 degrees C or chills

›New drainage or pus from the wound

›Finger feels colder than normal or turns pale or blue

›Spreading redness up the hand or arm

12References/r30

Guidelines and key sources

›Primary evidence sources

›Mehta P, Koyfman A, Long B. High Risk and Low Prevalence Diseases: Flexor Tenosynovitis. Am J Emerg Med. 2024. PMID 38147700

›Comprehensive EM-focused review

›Kanavel signs, management algorithm, outcomes

›Chapman T, Ilyas AM. Pyogenic Flexor Tenosynovitis: Evaluation and Treatment Strategies. J Hand Surg. 2019. PMID 31272698

›Hand surgery perspective on surgical approaches

›Draeger RW, Bynum DK. Flexor Tendon Sheath Infections of the Hand. JAAOS. 2012. PMID 22661567

›Orthopedic surgery review with anatomy and classification

›Systematic reviews

›Giladi AM, Malay S, Chung KC. Systematic Review of Management of Acute PFT. J Hand Surg Eur. 2015. PMID 25670687

›Best available evidence summary prior to 2020

›Forder BH, et al. Systematic Review of Treatment for PFT. JPRAS. 2024. PMID 39024677

›Updated systematic review including catheter irrigation comparisons

›Anderson GM, et al. Management of Pyogenic Flexor Tenosynovitis. JBJS Reviews. 2026. PMID 41996529

›Most current management review

›Supporting references

›Stevens DL, et al. IDSA Practice Guidelines for SSTI: 2014 Update. CID. 2014

›Includes PFT management recommendations

›Rerucha CM, et al. Acute Hand Infections. Am Fam Physician. 2019. PMID 30763047

›Antibiotic protocols and microbiology

›Yi A, et al. Radiographic Soft Tissue Thickness Differentiating PFT. J Hand Surg. 2019. PMID 30797654

›Volar-dorsal soft tissue ratio greater than 7 mm PPV 82%

›Hyatt BT, Bagg MR. Flexor Tenosynovitis. Orthop Clin N Am. 2017. PMID 28336044

›Anatomy, classification, and surgical pearls

›Coding reference

›ICD-10 M65.041 to M65.049 pyogenic flexor tenosynovitis by digit

›M65.041 right index finger

Evidence & Review