Otolaryngology Book

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Infectious RhinitisAka: Viral Rhinitis, Common Cold, Upper Respiratory Infection

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  1. Pathophysiology
    1. Infection of ciliated epithelial cells in nasal mucosa
    2. Nasal discharge results from mild cell inflammation
      1. Increased local production of mucus, Immunoglobulin
      2. Shedding epithelial cells
    3. Bacterial adherence increases with viral infection
      1. Superinfection risk (higher in smoke exposure)
    4. Wet weather and chilling do NOT increase infectivity
  2. Epidemiology
    1. Peak months (related to congregation in confined space)
      1. Temperate climate: September to March
      2. Tropics: Rainy season
    2. Annual Incidence
      1. Children: 6-8 URIs per season (higher in daycare)
      2. Adults: 2-4 URIs per season
    3. Course
      1. Incubation: 48-72 hours (may be as long as 7 days)
      2. Viral Shedding
        1. Peaks with symptoms
        2. Persists as long as 2-3 weeks
      3. Symptoms peak by days 3-5
    4. Transmission
      1. Aerosol transmission predominates
      2. Hand to hand to nose (and eye) transmission is common
        1. Hands are virally contaminated 60% of time
        2. Hand washing with virucidal agents is effective
      3. Fomite transmission (e.g. toys) is inconsistent
  3. Etiologies
    1. Most Common cause: Rhinovirus (30-50%)
    2. No Etiology identified (35%)
    3. Other Common causes (20-25%)
      1. Coronavirus
      2. Parainfluenza virus
      3. Adenovirus
      4. Enterovirus
      5. Influenza
      6. Respiratory Syncytial Virus (RSV)
    4. Less Common causes (10-15%)
      1. Chlamydia pneumoniae
      2. Mycoplasma pneumoniae
      3. Group A Streptococcal Pharyngitis
    5. Rare Causes
      1. Mumps
      2. Rubella
      3. Rubeola
      4. Cytomegalovirus (CMV)
  4. Differential Diagnosis
    1. Purulent Nasal discharge more than 10 days
      1. Acute Sinusitis
    2. Purulent cough, fever over 101, and acute debilitation
      1. Tracheobronchitis
      2. Pneumonia
      3. Influenza
    3. Laryngitis and non-productive cough more than 2 weeks
      1. Mycoplasma pneumoniae
      2. Chlamydia pneumoniae
    4. Raspy cough
      1. Pertussis (increasing Incidence in U.S.)
  5. Symptoms
    1. Nasal symptoms (precede other symptoms by 1-2 days)
      1. Sneezing
      2. Nasal congestion or stuffiness
      3. Nasal discharge increased
    2. Sore Throat: mild "scratchy" sensation
    3. Eye burning and eye tearing
    4. Dry, non-productive cough (40-60% of patients)
      1. Begins on days 2-3 and may persist for 7-10 days
    5. Generalized symptoms
      1. Malaise (mild)
      2. Muscle aches
      3. Low grade fever
    6. Less common symptoms
      1. Hoarseness
      2. Headache
      3. Chills
  6. Signs
    1. Low-grade fever less than 101 F (38.5 C)
    2. Nose
      1. Clear Nasal discharge
      2. Red, swollen nasal mucosa
    3. Throat with mild erythema
  7. Complications (1-2%; higher risk in smoke exposure)
    1. Bacterial Sinusitis
    2. Acute Otitis Media
    3. Bacterial Bronchitis
    4. Pneumonitis
    5. Bacterial Pneumonia
  8. Management
    1. General
      1. Cold Preparations do not change course
        1. No study shows shortened symptom course
        2. No study shows reduced secondary complications
      2. Antibiotics not indicated
        1. Consider discussing contingency plans
          1. Lays out plan for when antibiotics indicated
          2. Eliminates pressure for antibiotic prescription
        2. Example
          1. If symptoms persist beyond 14 days then...
          2. Antibiotics indicated for Acute Sinusitis
        3. Reference
          1. Mangione (2001) Arch Pediatr Adolesc Med 155:800
    2. Symptomatic therapy
      1. Nasal symptoms
        1. Decongestants reduce nasal congestion and discharge
          1. Topical Decongestants (e.g Afrin) for <4 days
          2. Oral Decongestants (e.g. Sudafed, Entex)
        2. Antihistamines are minimally useful in acute URI
          1. May predispose to Acute Sinusitis complication
        3. Vaseline reduces mucosal irritation and fissures
        4. Humidified air (e.g vaporizer) loosens discharge
      2. Cough
        1. Cough Suppressants (e.g. codeine, DM, Tessalon)
          1. Limit use (e.g. cough interfering with sleep)
          2. Unsuppressed cough may prevent complications
        2. Cough Expectorants
          1. Guaifenesin paradoxically reduces cough in URI
          2. Dicpinigaitis (2003) Chest 124:2178
      3. Sore Throat symptomatic management
      4. Muscle aches, fever, chills
        1. Acetaminophen or Ibuprofen
  9. Prevention
    1. Probiotic milk (with live culture lactobacillus)
      1. May reduce respiratory infections in children age <7
      2. Hatakka (2001) BMJ 322:1
  10. References
    1. Clemens (1997) J Pediatr 130:463

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