Arthritis
Rich Kaplan MD, MS, FACEP
The History
Comorbid diseases?
Recent infection?
IVDA?
Invasive procedures?
Tick exposure?
Case #1: Left knee pain
29 y.o. female
PHx anemia
L knee pain
1 week of fever, chills, myalgia and malaise
Severe pain and immobility over 4 days
Relief with motrin
PCP diagnosed viral illness
EM Pearls
Case#1: The Exam and Labs
39C, HR 130, RR 20, BP 112/66
L knee tender with decreased ROM
Labs:
WBC 8300 with 88% polys
Hct 26.6
L knee synovial fluid
WBC 56,000 with 98% polys
Gram positive cocci
What is this?
Septic Arthritis
The organisms
Staph aureus
Strep species
This case- Strep Group B ( agalactiae)
Neisseria gonorrhoeae
Hemophilus
Septic arthritis
Usually affects one joint
GC arthritis usually polyarticular
Knee, hip, shoulder, ankle, wrist, elbow
Look for:
Fever, tenderness,
Decreased ROM
Effusion, erythema, warmth
Watch for:
Immunocompromised
IVDA
RA
Synovial Fluid
Septic
Turbid
> 50,000 WBC
>75% polys
50,000
May have a lower WBC count with:
Early infection
Antibiotics
Immunocompromised status
Polys > 90% suggest infection
RA and crystal arthropathy may have high WBC
Synovial fluid
Gram stain
Diagnostic in 80% of g+ infections
Glucose
Normal 95% of serum glucose
Septic arthritis- synovial glucose men
Disseminated gonococcal
infection (DGI)
40% acute suppurative arthritis
Knee, wrist or ankle
Polyarthralgias may precede localization to 1 joint
Remaining cases: arthritis/dermatitis
Dermatitis
Painless erythematous macules or petechiae
Tenosynovitis
Migratory polyarthritis
Disseminated Gonococcal Infection
DGI
Hematogenous
Skin lesions alone or with:
Tenosynovitis or septic arthritis
Erythematous macule… necrotic, purpuric
vesicopustule
Arthralgia of one or more joints
Primarily hands or knees
Skin lesions in up to 70%
Resolve within 4 days regardless of antibiotics
Case #3: The hot, red ankle
21 y.o. female
Hot, red, painful near lateral malleolus
Similar pain right wrist 2 days earlier
Pustular lesion in web space between 4th
and 5th digit
Case #3: What should be
cultured?
Ankle synovial fluid
Blood
Genitalia
Leading edge of the cellulitis
Pustule
Culture the genitalia
Patient has arthritis-dermatitis syndrome
Form of disseminated gonococcal infection
More common in women
Look for:
Migratory arthritis or tenosynovitis and
pustular lesions
Gonococcal infection may rapidly destroy
a joint
DGI
Blood cultures- poor yield
Synovial culture ~50% positive
Genital culture positive 75%-90%
Nongonococcal septic arthritis
Medical emergency
May lead to rapid joint destruction
Mortality of 15%
IV drug use may seed:
SC
Costochondral
Sacroiliac
Nongonococcal septic arthritis
Abrupt onset
Progressive joint pain
Swelling, marked toxicity, fever
Pathogenesis:
Hematogenous
Contiguous
Direct traumatic implantation
Postoperative invasion of prothetic hardware
Nongonococcal pathogens
Gram-positive cocci
Staph aureus- 60%
Streptococci
Gram-negative bacilli- 20%
E coli
Pseudomonas
Anaerobes
Gout
Monosodium urate crystals precipitate within
joints
Inflammatory reaction
Severe joint pain, swelling, redness and warmth
MTP 60%
Ankle
Midfoot
Knee
Gout Precipitants
Increased purines
Enhanced cellular breakdown
Chemo
Alcohol
Joint trauma
Crystals
Monosodium urate
Needle shaped or elongated
Negative birefringence
CPPD
Rhomboid or rod-shaped
Weak positive birefringence
Crystal-Induced Arthritis
NSAID’s
Intraarticular steroids or Prednisone
Colchicine- for gout within 24 hours of
onset
1 mg then 0.5 mg every 2 hours to max of
8mg or bothersome side effects or
0.6 mg every hour for 3 doses
What about allopurinol and
probenecid?
Do not give in setting of acute or resolving
gout
The change in urate may exacerbate or
prolong an attack
What else can I do for crystal-
induced arthritis?
Joint rest and cold applications
Warm compresses exacerbate joint
inflammation
Consider opiate analgesics
Look for precipitants of acute gouty attacks
Alcohol
Purine-rich foods
Diuretics
Pseudogout
Calcium pyrophosphate dihydrate (CPPD)
Clinical course
Asymptomatic stippling of articular cartilage
on XRAY-
Chondrocalcinosis
Acute attacks of mono or oligoarticular
inflammatoryarthritis – pseudogout
Progressive degenerative joint changes
Pseudogout
Usually after 50
May involve single or multiple joints
Acute attacks – abrupt onset, marked
discomfort
Rheumatoid Arthritis
Inflammation in multiple joints
Most common- symmetric involvement
Hands, wrists, feet
Malaise, myalgia, weight loss
Anorexia
Fever
RA Complications
Neurologic
Subluxation C1,C2 (cord compression)
Entrapment neuropathy
Peripheral neuropathy
Carpal tunnel
Myositis
Necrotizing vasculitis
RA Complications
Musculoskeletal
Septic arthritis
Tendon rupture
Rupture of extensor tendons of the hand
Rheumatoid nodule
Synovial cyst behind the knee
Lung
Pleurisy
Effusion
Fibrosis
RA Complications
Cardiac
Pericarditis
Tamponade
Conduction defects
MI
RA Complications
Vasculitis
Small dermal vessels
Occasionally necrotizing vasculitis
Sjogren syndrome
Episcleritis
Acute Rheumatic Fever
Major Criteria
Carditis
Polyarthritis
Chorea
Erythema Marginatum
Macule that extends outward
Central clearing
SQ nodules
Acute Rheumatic Fever
Minor Criteria
Hx of RF
Fever
Arthralgia
Elevated sed rate
Prolonged PR
Which one is associated with
migratory arthritis?
Juvenile rheumatoid arthritis
Reiter syndrome
Rheumatic fever
Rheumatoid arthritis
SLE
Rheumatic Fever
Acute migratory or symmetric
polyarthralgia
Knees, ankles, elbows, wrists
RA
Involvement of small joints of hands or feet
predominate
Which of the following regarding
ARF is correct?
Caused by group B streptococcal infection
Fever is a major diagnostic criterion
Occurs during a course of acute
streptococcal infection
Primarily affects lower socioeconomic
groups
Steroids may be useful in treating
associated carditis
Steroids
Noninfectious immune diseasae
3-4 weeks after group A strep
Need 2 of 5 major criteria:
Carditis
Polyarthritis
Chorea
Erythema Marginatum
SQ nodules
Gonococcal Arthritis
1-3% with untreated gonococcal infection
DGI
Dermatitis
Tenosynovitis
Migratory polyarthritis
Joint involvement usually asymmetric
Painless nonpruritic skin rash
Lyme disease
Borrelia burgdorferi
Doxy
Erythema Chronicum Migrans in 60%
10% neuro abnormalities
Meningitis, encephalitis, cranial neuropathies
~10% cardiac abnormalities
AV block
Lyme disease
Single red macule …. to a large annular
lesion with a red outer border and central
clearing
Two weeks to 2 years after the initial skin
lesion
60% untreated patients… arthritis
Typically asymmetric
Oligo or monarticular
Large joints- most commonly the knee
Case #4: The “bug bite”
32 y.o. male
Fatigue, malaise, headache
10 days earlier- the bug bite
Annular erythematous lesion with central
clearing at the bite site
Which antibiotic?
Amoxicillin
Azithromycin
Ceftriaxone
Clindamycin
Erythromycin
Amoxicillin- Lyme disease
Stage I erythema chronicum migrans
Annular erythematous lesion with central
clearing
3-32 days after the bite
Doxy or amox for 10-21 days
Reiter Syndrome
Triad
NGU
Usually precedes arthritis
Asymmetric polyarthritis
Usually acute
Large joints of LE
Conjunctivitis
Polyarthritis syndromes
Enteric infections
Yersinia
Shigella
Salmonella
Clostridium difficile
Mycoplasma
Parvovirus
Serum Sickness
Usually 6-10 days after an antigenic
stimulus
Fever
Lymphadenopathy
Migratory arthralgia
May observe urticaria or angioedema
AIDS Arthritis
Painful, asymmetric, oligoarticular arthritis
of knees and ankles
Reiter syndrome
Lupus-like syndromes
Risk of pyogenic infections of joints
Tap the newly inflammed joint
Case #5: Knee pain- Can’t walk
6 y.o. male with knee pain
Unable to walk
38.5C
Right hip is tender
Limited ROM
WBC 15,000
ESR 30
Which of the following is most
clearly indicated?
Outpatient ortho referral in 24-48 hours
Discharge with motrin and advise bedrest
Hip joint aspiration under fluoroscopy
Ultrasound exam of hip and discharge if
there is no effusion
Hip MRI
Hip joint aspiration
Absence of effusion on U/S does not rule
out septic arthritis
Staph most commonly causes hip joint
infections
Infants
E coli
Children 6-24 months
H influenza
Toxic synovitis
Inability to walk
Resists hip movememnt
Does not appear toxic
Frequently with normal WBC count
ESR < 20