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Flashcards in Hand Infections Deck (50):

How do you classify hand infections

  • Acute vs chronic
  • By anatomic site
    • skin, subcut, deep space, tendon, muscle, 
  • By organism
    • bac, viral, fungal, parasitic, protozoal
  • By etiology
    • trauma, human/animal bute, IVDU, immunocompromise, post-op



What special tests are used for identification of fungal, mycobacteria and HSV infections?

  • Fungal: KOH, Giemsa, Silver stains
    • Hyphae, spores, mycelia
  • Mycobacteria/Nocardia: Ziehl-Niessen stain
  • HSV: Tzank smear


What are treatment principles of hand infection

  • Debridement
  • I&D
  • Splint, Elevation, Rest
  • Antibiotics
  • Early rehab
  • For surgical Tx
    • dont exsanguinated for tourniquet
    • local takes longer to work
    • plan for extension of incisions not over NV bundles
    • plan for multiple washouts
    • cultures from intraop samples
    • Joints - avoid aspiration over area of cellullits
    • Send joint fluid for cell count, C&S, Glc, protein


What are approaches to joints for washout of infection

  • Radio carpal jt - b/w 3/4 compartments
  • MCP jt - dorsal and split extensor
  • PIP jt - midaxial, split TRL, protect central slip
  • DIP jt - H or Y incision, protect TT


What are mimickers of infection to keep on DDX

  • Gout/Pseudogout
    • sent jt aspirate for crystals, Rheum referral
  • Acute calcific tendonitis
    • NSAIDs, Rheum referral
  • FB
  • Pyogenic granulosum
    • excise and cauterize base
  • Pyoderma gangrenosum
    • macult->papule w raise violaceous borders, associated w UC. 
    • Do not excise - treat w steroids and wound care
  • Spider bite
    • brown recluse spider leads to ST necrosis
  • Metastatc or 1' tumor
    • SCC BCC melnaoma KA
    • DP primary site for bone mets (source thyroid, prostate, breast, lung, kidney, colon


What are the 3 potential spaces for infections in the hand and forearm

  • Hand
    • thenar
    • hypothenar
    • midpalm
  • Forearm
    • Paronas space


What are the 9 spaces (includes 4deep and 5 superficials)


  • thenar
  • hypothenar
  • midpalm
  • Paronas


  • dorsal subcutaneous
  • dorsal subaponeurotic
  • interdigital webspace
  • radial bursa
  • ulnar bursa


Define boundaries of thenar space deep infection, symptoms/signs and treatment


  • Roof: D2 flexor sheath and palmar fascia
  • Floor: Adductor fascia
  • ulnar border: D3 MC vertical septum to palmar fascia
  • radial border: confluence of AddP fascia and muscle at insertion to PP

Findings: thumb abducted, pain w opp/abd


I&D across thenar crease and dorsal webspace


Define boundaries of midpalm space deep infection, symptoms/signs and treatment

MIDPALM - deep to flexors

Floor - Volar IO and MC 3,4,5

Roof - flexor sheaths 3,4,5 and palmar aponeurosis

Radial - vertical septum at D3 MC

Ulnar - hypothenar septum at D5 MC

Finding - loss of palmar concavity


I&D with incisoin from D3 webspace to pisiform


Define boudaries of Paronas space, findings and Treatment

  • volar wrist b/w PQ and long flexors
  • communicates w radial and ulnar bursa - horseshoe abscess- 
  • proximal extend to FDS insertion


What are complications of a hand infection


  • skin slough
  • extension to adjacent structures - OM, SA, tendon rupture, vessel thrombosis
  • amputation


  • recurrence
  • stiffness
  • degenrative arthritis


What is your management of a felon

= subcutaneous abscess of the finger pulp

Compx: OM, skin/pulp necrosis

Tx - I&D - incise on non-dominent side, break apart septae, keep intact flexor sheath, Abx, pack tid

--> can also consider longitudinal incision over most pointing aspect of felon


What is your management of a herpetic whitlow

= vesicles 2' to HSV1 (oral) HSV2 (genital)

Dx: Tzank smear of vesicle media or IF anti-HSV Ab

Tx: no I&D, dry gauze, topicla pancyclovir if immunocompromised, acyclovir if prodrome


What is your DDX of acute suppurative flexor tenosynovitis

  • gout/psudogout
  • inflammatory tenosynovitia
  • herpetic whitlow
  • felon
  • abscess


What is your management of acute flexor tenosynovitis suppurativa


  • IV abx, splint elevate observe and reqeunt reassessment


  • Catheter irrigation - incise prox to A1 distal to A4, irrigate w tid dressing change
  • ABX: ???
  • Early ROM


What is your management of a dog/cat bite



Rabies immunization


copious irrigation

delayed 1 wound healing

Xray to r/o FB

Abx: amox-clav (clavulin) OR if pen allergy, clindamycin + septra


What bacteria are associated w dog and cat bites?


  • s. aureus, s. viridans
  • bacteroides
  • pasteurella multicoda GNB
  • capnocytphaga canimorsus


- Pasteurella multicoda most common

plus similar to above

- cat scratch - rochalimaea henselea


What is your management of a human bite/fight bite




Xray for air in jt/FB

Clavulin OR if pen allergy, clindamycin + septra

I&D if joint involved, packing, delayed extensor repair


* most common pathogens

  • aerobics: s. aureus, epidermidis, strep
  • anaerobic:  bacteroides, peptococcus, peptosctreptococcus, Eikenella corrodens GNR,


What is your management of a necrotizing fasccitis

  • ABCs, ICU consult
  • Culture wound/blood
  • CBC, lytes Cr, LFT, CK, INR/PTT, lactate
  • Or - debridement devitalized tissue, repeat OR 24-48hrs later
  • IV abx - vanco+piptazo+clinda. Use 900mg IV q8h clinda for anaerobe, 4mu q4h penicillin for GAS


What are complications of septic arthritis

  • Stiffness, adhesions
  • OM
  • degenerative arthritis
  • boutonniere, mallet (pus erodes dorsally)
  • amputation


What will you send from sample for chronic wound to determine etiology

  • 1/2 in formalin (histo)
  • 1/2 not in formalin for 8pack micro diagnostic work-up:


  • ​Smears and stains:
    • Gram stain
    • AFB (ziehl neelsen)
    • Fungal stain (KOH)
  • Culture and sensitivity
    • aerobic
    • anaerobic
    • tuberculous mycobacteria at 37'
    • non-tuberculous mycobacteria at 30' (M.marinum) and at 42 (M.xenopi)
    • Mycotic culture media (Sabouraud dextrose agar) for sporotrichosis



What is your management of cat scatch disease?

  • Bartonella
  • Inoculation 1-3wks
  • lymphangitis, regional LAD
  • Self limiting


What is your management of Actinomycosis?

  • Actinomycosis Israelii
  • H&N, oral lesion ->abscess, + sinuses +sulfur yellow granules expressed, INVASIVE
  • Biopsy, Penicillin 6-12mths


What is your management of Tularemia?

  • Francisella Tularensis
  • Hx of animal bite non responisve to regular treatment w clavulin - >papule to ulceration/necrosis/lymphangitis
  • Tx: streptomycin/gentamycin


What necrotizing infection occurs from seawater contact/contamination?

  • Vibrio vulnificans -> necrotizing soft tissue infection - GN anaerobic rod
  • Tx: surgical debridement, +/- fasciotomies, DOXYCYCLINE


What is your treatment of onychomycosis?

  • Tinea infection - Trichophytan
  • nail thickening/seperation - occurs in DM/immunosuppressed/scleroderma
  • Dx: KOH of scrapings
  • Tx: antifungals topical, removal nail if persistent


What is your differential of a ulcerated verrucous nodule with lymphangitis wks-mths post injury, Hx of farming/gardening?


  • nocardiosis (dirt/soil)
  • tularemia  (animla contact)
  • atypical mycobacteria 
  • sporotrichosis schenckii (gardening)




What is your management of sporotrichosis?

  • sporothrix schenkii (fungal)
  • ulcerated raised verrucous nodule with lymphangitis, wks to months post injury while gardening
  • Dx: culture in Sabourard media
  • Tx: I&D of abscess if present, + amphotericin or itraconazole


What is your management of aspergillosis

  • Aspergillosis funigatis (hyphae)
  • necrotizing ulcer - usually at IV site - in immunocomp.
  • DDx nocardia, mucor
  • Dx: KOH prep
  • Tx - debridement w clear margins and amphotericin B


What is your management of mucormycosis

  • Mucorales rhizopus/rhizomucor
    • Triad: DM, gangrene, thrombosis + black discharge
  • Dx: biopsy
  • Tx:debridement + IV amphotericin


What is your management of mycobacterial infection?

  • TYPICAL: M. tuberculosis, bovis
  • ATYPICAL: M. marinum, Kansaii
  • Chronic granuloma + caseation
  • Dx: biopsy, culture (ZIehl Niessen stain)
  • Tx: Isoniazid, Rifampin, Ethambutal, Pyrazinamide


Where can tuberculosis infection occur and how does tx differ?

  • Cutaneous TB (most common site)
    • M. marinum, tuberculosis
  • TB tenosynovitis
    • M. Marinum most common
  • TB arthritis
    • M. Marinum most common
  • TB osteomyelitis


What is your management of cutaneous TB?

  • M. tuberculosis/marinum - Typical Myco infx
  • Hx of fresh water exposure
  • pustules on digits, LAD
  • Dx: skin biiopsy for ZN stain (AFB), C&S for mycobac 
  • Tx: 
    • Anti-tb Tx with Isoniazid, Rifampin, Ethambutal, Pyrazinamide


What is your management of TB tenosynovitis

  • M. Marinum most common
  • mimicks RA synovitis, commonly on flexors
  • Dx. biopsy for AFB, C&S
  • Tx: Synovectomy, Anti TB Tx: isoniazid, rifampin, ethambutal, pyrazinamide


What is your management of TB arthritis and osteomyelitis?

  • M. Marinum most common
  • WRIST most common  for arthritis- with little pain, mainly swelling and decreased ROM - subchondral erosions draining sinuses
  • MC and Phalanges most common for OM - bone loss, cystic lesions, pathologic fractue


  • Tx arthritis: control infection with antiTB meds then arthrodesis or arthorplasty
  • Tx OM: Anti TB meds


How do you classify fungal infections of the hand

By location

  • cutaneous (skin, nail)
  • Subcutaneous (sporotrochosis, chronic paronychia)
  • deep (mucomycosis)


What are three cardinal signs of Hansen's Diseasae (HD) - leprosy

  • Anesthetic skin patch
  • Nerve thickening
  • hypopigmented skin lesions (nodules)


What is the pathophysiology of HD?

  • Mycobacteria leprae, nasal droplet transmission
  • invade and proliferate in Schwann cells
  • causes mononeuritis multiplex
  • ulnar>median>radial
    • infectious neuropathy, immune neuropathy, compressive neuropathy
  • immune sys eradicates bacteria and repalces neural tissue with hyalinized fibrous tissue = nerve thickening
  • incubation 2-3yrs


How do you classify and diangose HD?

According to hosts immune response to M. leprae

  • Tuberculoid (high immunity)
  • Lepromatous (low immunity)
  • borderline (unstable/intermediate immunity)

Skin biopsy for dx

  • granulomas, thickened nerves
  • stain AFB



How do you treat HD

  • Eradicate M. leprae - Multidrug therapy - dapsone, rifampin, clofazinime x1yr
  • pain management - n. decompression, NSAIDS, gabapentin
  • prevention further nerve damage- steroids
  • restore sensation - n. transfer
  • restore function - ulnar n defomrity - claw hand - most common
  • psychiatric support


How do you define osteomyelitis?

def. inflammation of bone secondary to pyogenic organism, leading to bone destruction and subsequent new bone formation


What is an involucrum, a sequestrum, osteitis and brodies abscess

  • Involucrum: layer of newly formed living bone over area of necrotic bone 
  • Sequestrum: area of necrotic bone - defines chronic OM
  • Osteitis: infected bone cortex
  • Brodies abscess: localized focus  of infected bone following a subperiosteal infection


How do you classify OM

By etiology

  • hematogenous spread (peds)
  • contiguous spread form ST (vascular insufficiency - DM.PVD)
  • inoculation (post trauma/iatrogenic)


By chronicity

  • acute: within 2wks of disease and before sequestrae develop
  • subacute - 1-2 months 
  • chronic >3months


What bacteria are associated with different OM etiologies?

  • Post-trauma = s. aureus, epidermidis
  • Open F# = GNB, anaerobes
  • Fresh water/pool - m.marinuum
  • Sickle cell = salmonella
  • soil = sporotrichosis, enterobacter
  • foot - pseudomonas


List 4 factors protective against development of OM in post traumatic patient

  • adequate debridement
  • stabilization
  • dead space obliteration
  • early soft tissue coverage (5-7days)


What is your work-up for dx of OM?

  • Bone biopsy - before abx or 48hrs after stopping
  • Blood work - wbc, crp, esr, 
  • Investigations
    • Xray 1st - need 50% bone loss to see abnormality
    • CT 
    • MRI - more sensitive butmust be >12mth and no hardware
    • scintigraphy - can distinguish healing fractue from infected non union, subclincial OM


What are features of OM on Xray and CT?


  • periostitis
  • involucrum formation
  • cortical lucency


  • cortical defects
  • sequestra
  • fistula


What are your treatment goals and principles for OM?


  • Eradicate infection
  • Dead space obliteration
  • SST coverage
  • Fracture union
  • Function



  • Sugical debridement of all infected/devitalized tissue/bone + removal of hardware if fractur healed
  • Reconstruction of bone and ST
    • ST: Muscle flap - deadspace/vascular
    • Bone - exfix/1' graft or 2' graft
      • <1.5cm defect - 1' graftw cancellous bone
      • if 2', wait 3-6mths and place PMMA Abx beads
  • IV abx 6wks and until all clinical signs improve
    • if hardware in place, and s. aureux infection -> rifampin + ciprofloxacin
  • Amputation - if all tx fails and cannot restore fx


What is your treatment algorith for acute infection after ORIF

  • Bone not healed, hardware stable
    • Abx and leave hardware until union and clinically improved, then remove hardware
  • Bone not healed, hardware unstable
    • Abx, remove hardware and externally stabilize and plan for 2' recon once infx clear
  • Bone healed, hardware stable
    • Abx, remove hardware, control dead space