Rosen & Barkin's 5-Minute Emergency Medicine Consult (446 page)

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Seizures

CODES

• 320.2 Streptococcal meningitis
  
• 320.9 Meningitis due to unspecified bacterium
  
• 322.9 Meningitis, unspecified
  

BASICS

• Bacterial illness caused by
  Neisseria meningitidis
  
• Several forms of illness may occur
  
• Mild meningococcemia
  
• Overwhelming meningococcal sepsis
  
• Meningococcal meningitis
  
• Chronic/occult meningococcemia
  
• Septic arthritis
  
• Acquired from close contact with an infected individual or an asymptomatic carrier
  
• Intimate kissing and cigarette smoking are independent risk factors.
  

• N. meningitidis
  :
  
  • Serotypes A, B, C, D, H, I, K, L, X, Y, Z, 29E, and W135
    
  • Serotype B is most common in US
    
  • Majority of infections caused by A, B, C, X, Y, and W135
    
• Bacteria attach to and enter nasopharyngeal epithelial cells.
  
• Bacteria spread from the nasopharynx through the bloodstream via entry of vascular endothelium.
  
• Most circulating meningococci are eliminated by the spleen.
  
• Meningococci produce an endotoxin (lipooligosaccharide):
  
  • Involved in pathogenesis of the skin, adrenal manifestations, and vascular collapse
    
• Human oropharynx/nasopharynx is the only reservoir.
  
• Carrier usually has developed immunity to serotype-specific antibody (not immune to all serotypes):
  
  • Age <5 yr: 1% carrier rate
    
  • Age 20–40 yr: 30–40% carrier rate
    
  • Lower rate of immunity in children, which is reflected by the higher rates of infection
    
• Most common in fall and spring
  
• Increased incidence in military recruits and close living conditions
  
• Epidemics—ages 5–9 yr most/earliest affected
  

DIAGNOSIS

• “Mild” meningococcemia:
  
  • Most common
    
  • Preceded by upper respiratory infection
    
  • Fever, chills, myalgias/arthralgias, malaise
    
  • Often self-limited, resolving in several days
    
  • Can progress to meningitis (mortality rate 2–10%) or overwhelming sepsis without meningitis
    
• Overwhelming meningococcal sepsis:
  
  • 10% of overall meningococcemia cases
    
  • High mortality rate (20–60%)
    
  • Most deaths occur in 1st 48 hr
    
  • Sudden onset of illness and rapid progression of clinical course
    
  • Initial presentation may be mild:
    
    • Mild tachycardia
      
    • Mild tachypnea/respiratory symptoms
      
    • Mild hypotension
      
  • Fever, chills, vomiting, headache, rash, muscle tenderness
    
  • Toxic appearing
    
  • Infants: Lethargy, poor feeding, bulging fontanel
    
  • Rash:
    
    • Combination of purpura/ecchymosis
      
    • May later exhibit coalescence, necrosis/sloughing of the involved skin (purpura fulminans)
      
    • Petechiae (over skin, mucous membranes, conjunctivae) seen in 50–60%
      
    • Macules
      
    • Papules (scrapings of papules demonstrate the organism on Gram stain)
      
  • Deteriorate quickly over several hours:
    
    • Hypotension/shock
      
    • Acidosis
      
    • Acute respiratory distress syndrome (ARDS)
      
    • Disseminated intravascular coagulation (DIC)
      
  • Meningitis may or may not be present.
    
  • Waterhouse–Friderichsen syndrome:
    
    • Bilateral hemorrhagic destruction of adrenal glands
      
    • Vasomotor collapse
      
  • Acute renal failure:
    
    • From prolonged hypotension (low renal perfusion causing acute tubular necrosis)
      
• Chronic meningococcemia:
  
  • Uncommon
    
  • Well appearing
    
  • Recurrent fevers, chills, arthralgias over weeks to months
    
  • Intermittent rash—painful on the extremities
    
  • Migratory polyarthritis
    
  • Splenomegaly (20%)
    
  • Meningococcal meningitis:
    
  • Headache
    
  • Fever
    
  • Neck stiffness
    
  • Confusion
    
  • Lethargy
    
  • Obtundation
    
• Septic arthritis:
  
  • Occurs during active meningococcemia
    
  • Multiple joints involved
    
  • Joint pain, redness, swelling, effusion, fever, chills
    
  • Extremely limited or no range of motion
    
• Other meningococcal infections:
  
  • Occur with meningococcal infection elsewhere
    
  • Conjunctivitis—may occur alone
    
  • Sinusitis
    
  • Panophthalmitis
    
  • Urethritis
    
  • Salpingitis
    
  • Prostatitis
    
  • Pneumonia
    
  • Myocarditis/pericarditis:
    
    • Occurs late in onset
      
    • Usually associated with serogroup C
      

Progression of illness is variable and classifies illness into mild, overwhelming, and chronic.

• Tachycardia
  
• Hypotension, which may be mild initially
  
• Progressive, rapid deterioration
  
• Respiratory failure with ARDS picture
  
• Petechial rash 50–80%:
  
  • Involves axillae, flanks, wrists, ankles
    

• Do not allow workup (including delay in lumbar puncture) to postpone resuscitation and administration of antibiotics in suspected cases of meningococcemia.
  
• Suspect diagnosis in setting of dramatic clinical presentation.
  
• Gram stain and culture of:
  
  • Peripheral blood, CSF, sputum, urine, joint aspirate, or petechial/papular scrapings
    
  • Gram stain: Intracellular or extracellular gram-negative diplococci
    

• CBC:
  
  • Elevated WBCs initially; later may be suppressed in severe disease
    
  • Decreased platelet count when large areas of purpura/petechiae or DIC
    
• Electrolytes, BUN, creatinine, glucose
  
• CSF:
  
  • Gram stain, culture, protein and glucose, cell count with differential
    
  • Consistent with bacterial infection in meningococcal meningitis
    
• Arterial blood gases for acidosis, hypoxia
  
• Fibrinogen levels, fibrin degradation products, prothrombin time, partial thromboplastin time if DIC suspected
  
• Throat/nasopharyngeal swab:
  
  • Positive swab does not establish the diagnosis of meningococcemia.
    
• Analysis of buffy-coat layer of peripheral blood for bacteria if sepsis is suspected
  
• Blood culture:
  
  • Often negative with chronic meningococcemia
    
  • Positive in mild and overwhelming meningococcemia
    
• Immunoassays (beware false negatives)
  
• Polymerase chain reaction, especially useful when antibiotics given before specimen collection
  

CXR: For ARDS/pneumonia

Amputations and débridement of necrotic tissue and/or extremities may be necessary.

• Viral exanthem
  
• Vasculitis
  
• Mycoplasma
  
• Rocky Mountain spotted fever
  
• Toxic shock syndrome
  
• Henoch–Schönlein purpura
  
• Idiopathic thrombocytopenic purpura
  
• Dengue fever
  
• Disseminated gonococcal infection
  
• Influenza
  
• Streptococcus
  group A and B
  
• Thrombotic thrombocytopenic purpura
  

TREATMENT