Soft Tissue &
Musculoskeletal
Infections
in the Primary Care Setting
Patty W. Wright, MD
March 2011
Objectives

To familiarize participants with some of the most
common soft tissue and musculoskeletal
infections in the primary care setting, including
their diagnosis and treatment.
Case 1
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A 42 yo female who
works as a housekeeper
presents with a one year
history of swelling and
redness along the
borders of her nails
bilaterally.
What is the diagnosis?
How would you treat
her?
http://missinglink.ucsf.edu/lm/DermatologyGlossary/paronychia.html
Paronychia
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Infection of the skin
(epidermis) bordering
the nail
Typically associated
with trauma:
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Manicures
Ingrown nails
Dishwashing
Thumb sucking
http://en.wikipedia.org/wiki/File:Paronychia_argentea_(286232698).jpg
Chronic Paronychia
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Chronic paronychia typically due to eczema
Often have superinfection with yeast
(Candida)
Rx with steroid and antifungal creams
If no response, trial of oral antifungals with
topical steroids
Patient should avoid prolonged water
exposure to the hands
Consider alternative diagnoses such as
psoriasis
Acute Paronychia
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Commonly due
bacteria such to
Staph aureus or
Group A Strep
Soaks and surgical
drainage usually
enough
If severe, treat with
oral antibiotics
http://en.wikipedia.org/wiki/File:Paronychia.jpg
Case 2
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A 26 yo female hair
dresser develops
throbbing pain, swelling,
redness, & warmth in the
distal portion of her index
finger. She recalls that she
accidentally stuck herself
in the finger with her
scissors the day before.
What is the diagnosis?
How would you treat her?
http://drhem.com/2009/08/16/hand-case-3-1/
Felon
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Abscess of the pad (or pulp) of the tip of the finger
or toe
Significant pain, redness, and swelling in finger tip
Most commonly due to S. aureus
May spread to bone with resulting infection
(osteomyelitis)
Most commonly in thumb and index finger
Typically related to trauma: splinters, puncture
wounds, scraps or abrasions
Felon
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If early: elevation, soaks, and oral antibiotics
If late: rx as above plus surgical drainage
Culture the fluid to direct antibiotic therapy
Consider x-ray to rule out foreign body or
bone infection
Rx for 5-14 days depending on severity
Case 3
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A 33 year old female
presents with a red
pustular lesion on her
left 5th finger. The lesion
is tender and has been
present for almost a
week.
What additional
questions would you
like to ask this patient?
What pathogens are on
your differential
diagnosis?
Herpetic Whitlow
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Autoinoculation of HSV 1 or 2 into non-intact
skin
Health care workers at risk if not using
universal precautions
Abrupt onset of edema, erythema and
tenderness
Clear vessicles may coalesce become cloudy
Confirm with Tzanck test, viral culture, DFA,
or HSV PCR
Herpetic Whitlow
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Typically resolves in 2-3 weeks without rx
Treatment with antivirals (acyclovir,
famciclovir, valacyclovir) within 48hrs of onset
may lessen severity
Cover with dry dressing to avoid spread to
other areas
Recurs in up to 50% of patients, though
primary outbreak most severe
Case 4
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A 47 yo male construction
worker with a history of
“athletes' foot” presents to
the ED with redness, pain,
and swelling over his
ankle and lower leg.
What is the diagnosis?
How would you treat him?
http://battlegames.wordpress.com/2008/12/
Cellulitis
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Infection of the skin (dermis and hypodermis)
with some extension into the fatty,
subcutaneous tissues
Local signs: redness, swelling, warmth, and
tenderness +/- enlarged lymph nodes
Systemic signs may include low grade fevers,
chills, and body aches
Blood cultures rarely positive (2%)
Cellulitis
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Most common causes are Group A Strep and
S. aureus
Rx with iv antibiotics (vancomycin) for
inpatients
Rx with oral antibiotics for outpatient therapy
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If pt not systemically ill, has a normal immune
system, and has reliable follow up and access to
antibiotics
Remember that trim-sulfa may not be the best
coverage for Strep
Case 5
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A 50 yo male carpenter presents to the ER c/o pain
in his hand. He reports that a board fell on his hand
yesterday with some mild bruising. He awoke today
with pain so severe that he was unable to drive
himself to the ED.
What is the diagnosis?
How would you treat him?
Fasciitis / Myositis
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Fasciitis
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Myositis
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Infection of the fascia (thick layer of connective
tissue that surrounds the muscles, bones, nerves
and blood vessels)
Infection of the muscles
Rare: 500-1500 cases/year in the US
Clinical Presentation
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Fever, elevated heart rate, & low blood pressure
Local signs and symptoms such as swelling, large
blisters, crepitus, and pain out of proportion to the
exam
Fasciitis
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Imaging studies
such as CT or MRI
scans helpful if gas
present in the soft
tissues
Negative imaging
does not rule out
fasciitis
Fasciitis
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Type 1
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Mixed infection of aerobic and anaerobic bacteria
Seen in post surgical patients, diabetics and
patients with PVD
Type 2
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Monomicrobial infection caused by GAS or MRSA
in previously healthy patients
Fasciitis
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Surgery, Surgery, Surgery
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Re-exploration after 24 hours with repeat
debridement, if necessary
Blood pressure support and ICU care, if
indicated
Antibiotic therapy
Fasciitis
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Empiric Antibiotics
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Target
1.
Core antibiotic:
Imipenem,
Meropenem, Pip-tazo
1.
Sensitive Gram
positives, Gram
negatives & anerobes
2.
Secondary antibiotic:
Vancomycin, Linezolid,
Daptomycin
2.
MRSA
3.
Clindamycin and IVIG
3.
Group A Streptococcus
toxin
Case 6
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An 28 yo male
landscaper presents with
pain and swelling along
the length of his middle
finger. He reports that
his pain is most severe
when he tries to move
the finger.
What is the diagnosis?
How would you treat
him?
Infectious
Tenosynovitis
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Infection of the fluidfilled sheath that
surrounds the tendon
Leads to swelling and
pain of the finger (or
toe) especially with
movement
http://www.sportnetdoc.com/injury/07-06.htm
Acute Infectious
Tenosynovitis

Kanavel signs for pyogenic flexor
tenosynovitis:
 Uniform symmetric swelling of the digit
 Digit held in partial flexion at rest
 Excessive tenderness along the entire
tendon sheath
 Pain along the sheath with passive digit
extension
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Most clinically reproducible sign
Acute Infectious
Flexor Tenosynovitis
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Most commonly related to trauma, particularly
at the flexor crease
Most common pathogens are Staph and
Strep
Polymicrobial infections possible in DM or
immunocompromised
May occur following hematogenous spread,
particularly with N. gonorrhoeae
Early stage may respond to elevation,
splinting, and iv abx
Acute Infectious
Tenosynovitis
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I&D if…
 DM
 Immunocompromised
 No improvement within 12-24 hrs of abx
therapy
Gram stain and culture to direct abx therapy
Rx empirically with vancomycin and
quinolone (ciprofloxacin, levofloxacin) then
tailor regimen to cx results
Chronic Infectious
Tenosynovitis
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Often due to atypical mycobacterial or fungal
infections
Empiric therapy is difficult given wide
spectrum of etiologies
Cultures for AFB and fungi essential to
diagnosis and treatment
Pathology with special stains may be helpful,
but cultures best
Case 7
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A 44 yo former roofer is
paralyzed following a fall with
spinal cord injury 5 years ago.
Recently he developed a small
ulceration on his lower back
which has progressed despite
local care. On exam, the
wound probes to the bone.
What is the diagnosis?
How would you treat him?
http://boneandspine.com/orthopaedic-images/clinical-photograph-of-stage-iv-sacral-bed-sore-in-a-patient-of-cervical-spine-injury/
Osteomyelitis
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May be acute (progressing over days) or chronic
(progressing over weeks to months)
May occur from direct spread of infection or
spread of infection through the blood stream
 Hematogenous (20%)
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Contiguous with vascular insufficiency (30%)
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Children
Diabetic neuropathy
Contiguous without vascular insufficiency (50%)
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Trauma (natural or iatrogenic)
Haematogenous Osteomyelitis
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PAIN is primary symptom
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Frequently progressive over several months
Constitutional symptoms or local edema/erythema
less common
Long bones most common site in children
Vertebrae most common site in adults
Single pathogen most likely
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S. aureus most common
P. aeruginosa with injection drug use
Osteomyelitis
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Definitive diagnosis
requires bone biopsy
Often diagnosed clinically
based on exam, labs, and
imaging
WBC count rarely elevated
Sedimentation rate (ESR)
and C-reactive protein
(CRP) measures of
inflammation are useful for
serial monitoring
www4.path.utah.edu
“Probe Test” of Osteomyelitis
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Obtain sterile probe
Gently insert into
deepest portion of ulcer
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Sens = 66%
Spec = 85%
PPV = 89%
NPV = 56%
Exposed bone is
infected bone
Osteomyelitis Imaging – Xrays
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Cheap and easy
Able to evaluate for
foreign body
Not useful for acute
osteomyelitis
Radiolucent areas do not
appear until 50-75%
bone loss
Osteomyelitis Imaging –
Technetium Bone Scan
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More sensitive than plain radiography
Taken up in areas with
 Increased blood flow
 New bone formation
May be positive as early as 48 hours
after infection
Gallium and indium scans less sensitive
Osteomyelitis Imaging –
CT and MRI scans
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Excellent bone
resolution
Hindered by presence
of prosthetic material
MRI preferred for
small bones of
hands/feet
flickr.com/photos/69918874@N00/2208251162/
Osteomyelitis
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Treatment typically involves…
 Surgical debridement followed by aggressive
wound care
 Prolonged antibiotic therapy
 6 weeks minimum, may extend for months
depending on clinical course
 IV antibiotics needed for acute osteomyelitis
 Oral antibiotics alone may be indicated for
some chronic osteomyelitis
 Unless definitive pathogen identified by bone
biopsy, broad spectrum coverage indicated
Case 8
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An 82 year old woman
presents with swelling and
pain in her left knee. She
underwent a total knee
arthroplasty 10 years ago for
OA with a revision 3 years
ago for loosening of the
hardware.
What is the diagnosis?
How would you treat her?
Epidemiology of
Prosthetic Joint Infections
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1-3% of primary joint replacements
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Knee = 1-2%
Hip = 0.3 – 1.3%
Shoulder - <1%
3-6% of revision procedures
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Knee = 6%
Hip = 3%
Prosthetic Joint InfectionsTiming of Infection
Classification
Characteristic
Early (<3 months)
Typically acquired at surgery and associated
more virulent organisms
e.g. Staphylococcus aureus, Gram-negative
bacilli
Delayed (3 – 24 months)
Typically acquired at surgery and associated
with less virulent organisms
e.g. coagulase-negative Staphylococci,
Proprionibacterium acnes
Late (>24 months)
Usually associated with haematogenous
spread from distant infection
Prosthetic Joint InfectionsClinical Presentation
PAIN
Present in >90% cases
 Night pain more concerning for
infection
 Start-up pain appears more
consistent with aseptic loosening
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Prosthetic Joint InfectionsDiagnosis
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Primary differentiation is between infection
and aseptic loosening
Rely on “totality of circumstances”
 Clinical exam
 Laboratory data
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ESR/CRP
Culture of joint fluid
Imaging
Prosthetic Joint InfectionsTreatment Approach
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Acute infection (<4 wks)
AND stable implant
AND no sinus tract…
Consider debridement
with retention followed
by IV antibiotics +/additional PO antibiotics
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Chronic PJI…
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Joint removal is
necessary for cure
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Debridement with
retention followed by
IV antibiotics then
suppressive PO
antibiotics may be
considered in
debilitated patients who
cannot tolerate joint
removal
Summary
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Paronychia & felons are infections of the
fingers/toes which often improve with simple I&D
and/or po abx
Treatment for cellulitis should include coverage of
Staph and Strep
Fasciitis is a surgical emergency & should be
treated with very broad-spectrum antibiotics
Acute infectious tenosynovitis is typically due to
bacteria; chronic is often due to mycobacteria or
fungi
Exposed bone is infected bone
Osteomyelitis and PJI’s typically require surgery
and long-term abx therapy