Hand Infections Flashcards
1
Q
How do you classify hand infections
A
- 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
2
Q
What special tests are used for identification of fungal, mycobacteria and HSV infections?
A
- Fungal: KOH, Giemsa, Silver stains
- Hyphae, spores, mycelia
- Mycobacteria/Nocardia: Ziehl-Niessen stain
- HSV: Tzank smear
3
Q
What are treatment principles of hand infection
A
- 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
4
Q
What are approaches to joints for washout of infection
A
- 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
5
Q
What are mimickers of infection to keep on DDX
A
- 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
6
Q
What are the 3 potential spaces for infections in the hand and forearm
A
- Hand
- thenar
- hypothenar
- midpalm
- Forearm
- Paronas space
7
Q
What are the 9 spaces (includes 4deep and 5 superficials)
A
DEEP
- thenar
- hypothenar
- midpalm
- Paronas
Superficial
- dorsal subcutaneous
- dorsal subaponeurotic
- interdigital webspace
- radial bursa
- ulnar bursa
8
Q
Define boundaries of thenar space deep infection, symptoms/signs and treatment
A
THENAR SPACE
- 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
Tx:
I&D across thenar crease and dorsal webspace
9
Q
Define boundaries of midpalm space deep infection, symptoms/signs and treatment
A
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
Tx
I&D with incisoin from D3 webspace to pisiform
10
Q
Define boudaries of Paronas space, findings and Treatment
A
- volar wrist b/w PQ and long flexors
- communicates w radial and ulnar bursa - horseshoe abscess-
- proximal extend to FDS insertion
11
Q
What are complications of a hand infection
A
EARLY
- skin slough
- extension to adjacent structures - OM, SA, tendon rupture, vessel thrombosis
- amputation
LATE
- recurrence
- stiffness
- degenrative arthritis
12
Q
What is your management of a felon
A
= 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
13
Q
What is your management of a herpetic whitlow
A
= 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
14
Q
What is your DDX of acute suppurative flexor tenosynovitis
A
- gout/psudogout
- inflammatory tenosynovitia
- herpetic whitlow
- felon
- abscess
15
Q
What is your management of acute flexor tenosynovitis suppurativa
A
Early
- IV abx, splint elevate observe and reqeunt reassessment
Late
- Catheter irrigation - incise prox to A1 distal to A4, irrigate w tid dressing change
- ABX: ???
- Early ROM
16
Q
What is your management of a dog/cat bite
A
History
tetanus
Rabies immunization
Culture
copious irrigation
delayed 1 wound healing
Xray to r/o FB
Abx: amox-clav (clavulin) OR if pen allergy, clindamycin + septra
17
Q
What bacteria are associated w dog and cat bites?
A
DOG
- s. aureus, s. viridans
- bacteroides
- pasteurella multicoda GNB
- capnocytphaga canimorsus
CAT
- Pasteurella multicoda most common
plus similar to above
- cat scratch - rochalimaea henselea
18
Q
What is your management of a human bite/fight bite
A
History
Tetanus
Culture
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,
19
Q
What is your management of a necrotizing fasccitis
A
- 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
20
Q
What are complications of septic arthritis
A
- Stiffness, adhesions
- OM
- degenerative arthritis
- boutonniere, mallet (pus erodes dorsally)
- amputation
21
Q
What will you send from sample for chronic wound to determine etiology
A
- 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
22
Q
What is your management of cat scatch disease?
A
- Bartonella
- Inoculation 1-3wks
- lymphangitis, regional LAD
- Self limiting
23
Q
What is your management of Actinomycosis?
A
- Actinomycosis Israelii
- H&N, oral lesion ->abscess, + sinuses +sulfur yellow granules expressed, INVASIVE
- Biopsy, Penicillin 6-12mths
24
Q
What is your management of Tularemia?
A
- Francisella Tularensis
- Hx of animal bite non responisve to regular treatment w clavulin - >papule to ulceration/necrosis/lymphangitis
- Tx: streptomycin/gentamycin
25
What necrotizing infection occurs from seawater contact/contamination?
* Vibrio vulnificans -\> necrotizing soft tissue infection - GN anaerobic rod
* Tx: surgical debridement, +/- fasciotomies, DOXYCYCLINE
26
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
27
What is your differential of a ulcerated verrucous nodule with lymphangitis wks-mths post injury, Hx of farming/gardening?
DDX
* nocardiosis (dirt/soil)
* tularemia (animla contact)
* atypical mycobacteria
* sporotrichosis schenckii (gardening)
28
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
29
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
30
What is your management of mucormycosis
* Mucorales rhizopus/rhizomucor
* Triad: DM, gangrene, thrombosis + black discharge
* Dx: biopsy
* Tx:debridement + IV amphotericin
31
What is your management of mycobacterial infection?
* MOST COMMON CHRONIC HAND INFECTION
* TYPICAL: M. tuberculosis, bovis
* ATYPICAL: M. marinum, Kansaii
* Chronic granuloma + caseation
* Dx: biopsy, culture (ZIehl Niessen stain)
* Tx: Isoniazid, Rifampin, Ethambutal, Pyrazinamide
32
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
33
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
34
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
35
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
36
How do you classify fungal infections of the hand
By location
* cutaneous (skin, nail)
* Subcutaneous (sporotrochosis, chronic paronychia)
* deep (mucomycosis)
37
What are three cardinal signs of Hansen's Diseasae (HD) - leprosy
* Anesthetic skin patch
* Nerve thickening
* hypopigmented skin lesions (nodules)
38
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
39
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
40
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
41
How do you define osteomyelitis?
def. inflammation of bone secondary to pyogenic organism, leading to bone destruction and subsequent new bone formation
42
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
43
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
44
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
45
List 4 factors protective against development of OM in post traumatic patient
* adequate debridement
* stabilization
* dead space obliteration
* early soft tissue coverage (5-7days)
46
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
47
What are features of OM on Xray and CT?
Xray
* periostitis
* involucrum formation
* cortical lucency
CT
* cortical defects
* sequestra
* fistula
48
What are your treatment goals and principles for OM?
GOALS
* Eradicate infection
* Dead space obliteration
* SST coverage
* Fracture union
* Function
PRINCIPLES
* 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
49
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
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