Common Infections

Pharyngitis (Sore Throat)

• Inflammation of the oropharynx
• Wide range of organisms:
  • Viral
    • Adenovirus, rhinovirus, influenza virus, RSV, EBV, coxsackie virus, HSV, CMV, HIV.
    • Most common cause - year around.
  • Bacterial
    • Group A beta-hemolytic Strep (most common bacterial cause 5-15% adult, 50% peds, usually in winter)
    • Croup C and G beta-hemolytic Step, N. gonorrheae, Chlamydia pneumoniae, Mycoplasma pneumoniasee, Corynebacterium diphtheriae.
  • See Streptococcal Pharyngitis
• If suspect EBV (mononucleosis) - do peripheral blood smear ("monospot")
  • Giving Ampicillin produces rash.
  • Rest, supportive care (tylenol, NSAIDs)
  • Avoid contact sports until splenomegaly resolves - to prevent splenic rupture.

Streptococcal Pharyngitis

Symptoms:

• Sore Throat
• Fever
• Enlarged Tonsils + exudate (could be tonsillar abscess)

DDx

• Strep Pharyngitis
• Mononucleosis
• STI: gonococcal or chlamydial
• Viral Pharyngitis

Dx:  

• Use Rapid Strep Test (in-office) 95% sensitivity, 50-90% specificity.
  • If positive - treat
  • if negative - take culture, treat if positive. 
 
• Who to swab for B-Hemolytic strep?  - Use Modified Santor Score:

  • Modified Centor Score
    Temp >38 Tonsillar Swelling or Exudate Absence of Cough Tender anterior lymph nodes Interpretation: 0-1 --> Do not swab (2.5% risk of strep) 2-3 --> Swab, treat if positive (28% risk of strep) 4 --> Likely strep, treat (53% risk of strep)

•  
• How to distinguish strep from mono?
  • Anterior cervical lymph nodes for strep, and both anterior and posterior for mono
  • Mono spot
  • Blood CBC - Atypical lymphocytosis in mono
  • LFTs elevated in mono
• Complications
  • Rheumatic fever
  • Glomerulonephritis
  • Suppurative complications (abscess, sinusitis, otitis media, penumonia)
  • meningitis
  • impetigo

Tx:

• Drugs:
  • Penicillin --> Cheapest penicillin 300mg qid x10 days
  • Amoxicillin 500mg tid x10 days
  • Cephalosporins (cost 50-60x more)
  • Macrolides (cost 30x more) - azithromycin 500mg first day, then 250mg x5 days (take two pills on day 1)
  • Amox-Clav - (50x more expensive, rarely used in this)
• Why do we treat? - to prevent Rheumatic Fever, however evidence shows we cannot prevent post-strep glomerulonephritis

Sinusitis

• Presentation:
  • Congestion +/- nasal discharge
  • Fever
    Headache, sinus pain    
  • Post-nasal drip
• Causes:
  • Strep pneumoniae
  • H. influenza
  • Staph aureus
  • Moraxella catarrhalis
  • Viral

DDx

• Viral URI
• Allergies
• etc.

Dx:

TREAT IF >7 DAYS

• What increases the likelihood the pt has sinusitis?
  • if lasts 10-14d with no improvement
  • If nasal congestion, nasal pain, purulent discharge after day 5

Tx:

• Acute sinusitis: (i.e. ~7 days)
  • Symptom management
    • Analgesics
    • Decongestants such as chlorpheniramine.
    • Intra-nasal steroids. (try others first).
  • Most resolve in 7-10 days.
  • Abx if complicated by fever or worsening symptoms (efficacy not well documented).
    • First line: Amoxicillin 500mg tid 7-10 days
    • Recent review 2009 - 10 days of rhinosinusitis sx: abx = watchful waiting.
• Why do we treat? - can get complications such as:
  • chronic sinusitis
  • tracking to CNS --> meningitis, cavernous sinus thrombosis etc..
• Imaging:
  • Typically reserved for those with a complicated presentation (headache, visual changes etc..)
• Note:
  • Nasal cultures: not shown to help identify organism. 

Acute Otitis Media

• Presentation:
  • Common triad: otalgia, fever, conductive hearing loss
  • May include poor sleep, irrititability, poor feeding
  • Hyperemia, opaque bulging tympanic membrane on direct otoscopy
• Organisms:
  • Strep pneumoniae
  • H. influenza
  • Moraxella catarrhalis

Tx:

• 80-90% will resolve with watchful waiting in 48-72hrs..treat fever.  Watch for rash, drowsiness, vomiting, SOB
• To treat or not to treat:

  • Acute Otitis Media Guidelines
    <6mo of age - Antibiotic therapy 6mo-2yrs - Antibiotic therapy if certain of diagnosis.  Observation if uncertain diagnosis >2hrs - Antibiotic therapy if severe illness.  Observation if non-severe or uncertain diagnosis.

    (AAP & AAFP Clinical Practice Guidelines)

  • Reasons to treat right away:
    <6mo Fever >39C Perforation Toxic Unreliable parents symptoms not improving after 2-3 days.

• Drugs:
  • 1st line: Amoxicillin 80-90 mg/kg/d  (use macrolides if penicillin allergy)
  • 2nd line: Amoxicillin-clavulanate (6.4 mg/kg/d)
  • Antipyretic: 10-15 mg/kg acetaminophen, max 75mg/kg/day
• Antipyretics/Analgesics: Acetaminophen 10-15mg/kg/dose PO Q4H prn
• If TM perforation, use drops.

Bronchitis (Acute)

• Symptoms
  • SOB
  • Productive cough
  • Fever
• Etiology
  • 80% viral: rhinovirus, coronavirus, adenovirus, influenza, parainfluenza, RSV
  • 20% bacterial: M. pneumoniae, C. pneumoniae, S. pneumoniae
• Dx: clinical, R/O pneumonia, asthma, COPD
• Tx:
  • frequent hand washing, smoking
  • Symptom relief: rest, fluids (3-4L/d), humidity, analgestics, antitussives
  • bronchodilators can relieve sx.
  • Abx not supported in literature unless chronic or comorbidities.