Rosen & Barkin's 5-Minute Emergency Medicine Consult (427 page)

• Admission is often necessary for definitive care.
  
• Open fracture, presence of multiple trauma, or other more serious injuries mandates admission.
  

Patients with closed dislocations or fractures that have been adequately reduced and immobilized in the ED may be discharged with orthopedic follow-up.

• For those reduced and discharged with splint, follow-up with orthopedics.
  
• No return to play until fully healed.
  

• Failure to diagnose wrist dislocations.
  
• Missed median nerve injury.
  
• Avascular necrosis of the lunate (Kienböck disease)
  
• Degenerative joint disease.
  

• Budoff JE. Treatment of acute lunate and perilunate dislocations.
  J Hand Surg Am
  . 2008;33(8):1424–1432.
  
• Marx JA, Hockberger RS, Walls RM, et al., eds.
  Rosen’s Emergency Medicine: Concepts and Clinical Practice
  . 7th ed. Philadelphia, PA: Mosby, Elsevier; 2010.
  
• Mayfield JK, Johnson RP, Kilcoyne RK. Carpal dislocations: Pathomechanics and progressive perilunar instability.
  J Hand Surg Am
  . 1980;5(3):226–241.
  
• Perron AD, Brady WJ, Keats TE, et al. Orthopedic pitfalls in the ED: Lunate and perilunate injuries.
  Am J Emerg Med
  . 2001;19(2):157–162.
  

CODES

• 833.02 Closed dislocation of radiocarpal (joint)
  
• 833.09 Closed dislocation of wrist, other
  

BASICS

• Most common tick-borne illness in North America
  
• Endemic in Northeast, Upper Midwest, and northwestern California
  

• Peak April–November; 80–90% in summer months
  
• Spirochete
  Borrelia burgdorferi
  introduced by Ixodes tick:
  
  • Ixodes dammini
    (deer tick) most common
    
• <50% of patients recall tick bite.
  
• Pathogenesis—combination of:
  
  • Organism-induced local inflammation
    
  • Cytokine release
    
  • Autoimmunity
    
• No person-to-person transmission
  
• Borrelia miyamotoi,
  a spirochete related to
  B. burgdorferi,
  has recently been described as causing disease similar to Lyme disease.
  

DIAGNOSIS

Stage I (early):

• Onset few days to a month after tick bite (arthropod transmission)
  
• 30–50% of patients recall tick bite.
  
• Erythema chronicum migrans (ECM):
  
  • Pathognomonic finding:
    
    • Bull’s-eye rash
      
  • Maculopapular, irregular expanding annular lesion:
    
    • Single or multiple
      
    • Central clearing with red outer border
      
    • Diameter >5 cm
      
• Regional adenopathy
  
• Low-grade intermittent fever
  
• Headache
  
• Myalgia
  
• Arthralgias
  
• Fatigue
  
• Malaise
  

Stage II (secondary, disseminated):

• Days to weeks after tick bite
  
• Intermittent and fluctuating symptoms with eventual disappearance
  
• Triad of aseptic meningitis, cranial neuritis, and radiculoneuritis:
  
  • Facial (Bell) palsy most common cranial neuritis
    
  • May present without rash
    
  • Prognosis generally good
    
• Cardiac:
  
  • Tachycardia
    
  • Bradycardia
    
  • Atrioventricular block
    
  • Myopericarditis
    

Stage III (tertiary, late):

• Onset >1 yr after disease onset
  
• Acrodermatitis chronica atrophicans:
  
  • Extensor surfaces of extremities, especially lower leg
    
  • Initial edematous infiltration evolving to atrophic lesions
    
  • Resembles scleroderma
    
• Arthritis:
  
  • Brief arthritis attacks
    
  • Monoarthritis
    
  • Oligoarthritis
    
  • Occasionally migratory
    
  • Most common joints (descending order):
    
    • Knee
      
    • Shoulder
      
    • Elbow
      

Other:

• GI:
  
  • Hepatitis
    
  • Right upper quadrant pain
    
• Ocular:
  
  • Keratitis
    
  • Uveitis
    
  • Iritis
    
  • Optic neuritis
    
• Jarisch–Herxheimer reaction:
  
  • Worsening of symptoms a few hours after treatment initiated
    
  • More common in patients with multiple ECM lesions
    
• Babesiosis occurs simultaneously in endemic areas.
  

Persistent Lyme disease:

• Articular and neurologic symptoms despite treatment:
  
  • Chronic axonal polyneuropathy or encephalopathy
    

Recurrent Lyme disease:

• Relapse despite treatment
  
• 2nd episodes less severe
  

• More likely than adults to be febrile
  
• Only 50% of children with arthralgias have history of ECM.
  
• Facial palsy is accompanied by aseptic meningitis in 1/3.
  
• Asymptomatic cardiac involvement with abnormal ECGs
  
• Appropriately treated children have excellent prognosis for unimpaired cognitive functioning.
  
• Untreated children may have keratitis
  

No clear evidence that Lyme disease during pregnancy causes harm to fetus

• History of tick bite in endemic areas
  
• Flu-like illness in the summer
  

• Rash
  
• Joint, cardiac, and neurologic findings in later organ involvement
  

• Clinical diagnosis:
  
  • Presence of ECM obviates serologic tests.
    
• Careful search for tick
  
• Lumbar puncture when meningeal signs
  
• Arthrocentesis for acute arthritis
  
• ECG
  

• CBC:
  
  • Leukocytosis
    
  • Anemia
    
  • Thrombocytopenia
    
• ESR:
  
  • >30 mm/hr
    
  • Most common lab abnormality
    
• Electrolytes, BUN, creatinine, glucose
  
• Liver function tests:
  
  • Elevated liver enzymes (γ-glutamyl transferase most common)
    
• Culture:
  
  • Low yield
    
  • Not indicated
    
• CSF:
  
  • Pleocytosis
    
  • Elevated protein
    
  • Obtain CSF spirochete antibodies.
    
• Special tests:
  
  • Serology:
    
    • Obtain ELISA, immunofluorescence assay, and western blot when disease is suggested without ECM lesion.
      
    • Antibodies may persist for months to years.
      
    • Positive serology or previous Lyme disease does not ensure protective immunity.
      
  • Polymerase chain reaction assay:
    
    • Highly specific and sensitive
      
    • Not available for routine use
      
  • Joint fluid:
    
    • Cryoglobulin increased 5-fold compared with serum
      
  • Joint films may show soft tissue, cartilaginous, osseous changes.
    

• Other tick-borne illnesses:
  
  • Deer tick usually larger (1 cm) than Ixodid ticks (1–2 mm)
    
  • Rocky Mountain spotted fever
    
  • Tularemia
    
  • Relapsing fever
    
  • Colorado tick fever
    
  • Tick-bite paralysis
    
• Rheumatic fever:
  
  • Rash of erythema marginatum
    
  • Temporomandibular joint arthritis more common than in Lyme disease
    
  • Valvular involvement rather than heart block
    
  • Chorea may be isolated finding.
    
• Viral meningitis
  
  • Syphilis
    
  • Septic arthritis
    
  • Parvovirus B19 infection—polyarticular arthritis
    
  • Infectious endocarditis
    
  • Juvenile rheumatoid arthritis
    
  • Reiter syndrome
    
  • Brown recluse spider bite
    
  • Fibromyalgia
    
  • Chronic fatigue syndrome
    

TREATMENT