• five families of virus
  • parainfluenza
  • respiratory syncytial virus
  • rhinovirus (MAJOR)
  • coronavirus (second most)
  • enterovirus
    • influenza, adenovirus associated with more severe illness

Most etiologies are undiscovered though

• seasonal incidence- annual epidemics occur in colder months
  • rhinovirus: ealry fall, mid spring
  • coronavirus: winter
• attack rates
  • highest in young children in nursery school
  • adults average 2-4 colds/yr
  • children average 6-8 colds/yr

• main reservoir: young children when they acquire new viral strands from school mates
• secondary attack rates of family members vary
  • related risk factors: age, immunity
• means of transmission
  • direct contact with infectious secretion
  • airborne droplets

• characteristic changes in sloughed of epithelial lining
  • progressive nuclear pyknosis
  • formation of inclusion bodies
• destructive effect on mucus membrane
• chemical mediators (PG's, histamines, IL 1,6,8) and neurological reflexes such as parasympathetic pathway play a role

• incubation period: 12-72 hrs (can be rapid)
• nasal discharge and obstruction, sneezing, sore throat, cough, fever, loss of sense of smell/taste
• median duration is 1 week
• in young children, parainfluenza and RSV can cause viral pneumonia, croup, and bronchiolitis

• clinical symptoms
• marked pharyngeal injection or exudate warrants rapid Ag detection or throat culture for group A beta hemolytic strep
• serological dx- 4 fold rise in Ab titers from acute and convelescent sera
• rapid fluorescent Ab tests RSV, influenza, parainfluenza, adenoviruses

• vasoconstrictors
• antihistamines
• antipyretics

• viral
  • rhinovirus
  • adenovirus
  • influenza
  • parainfluenza
  • coxackievirus A
  • HSV
  • EBV
  • CMV
• bacterial
  • group A and C beta hemolytic strep
  • N. gonorrhea
  • Corynebacterium diptheriae
  • Mycoplasma
  • anaerobic bacteria

• rhinovirus- stimulate pain nerve endings through release of inflammatory mediators
• adenovirus, coxackievirus A- direct invasion of mucosa
• group A strep- release of erythrogenic toxin, hemolysins
• Corynebacterium diptheriae- fibrosis pseudomembrane

• group A strep symptoms may be mild
  • when severe: pharyngeal pain, odynophagia, fever, pharynx is often erythematous with an exudate, cervical adenopathy, leukocytosis may occur
• viral pharyngitis
  • usual mild symptoms, except influenza
  • EBV and adenoviruses- cause exudative pharyngitis
  • coxsakie virus and HSV- may be distinguished with presence of vesicles

• main objective to distinguish viral from strept
• rapid Ag detection tests for strep using a throat swab
  • 90% specific
  • 60-95% sensitive
• negative test should be followed by throat culture

• strept pharyngitis- 10 day course of penicillin
• viral pharyngitis- supportive

• definition- rapid progressive cellulitis of epiglottis that can potentially occlude airway
• etiology
  • H. influenza type B is isolated from blood or epiglottis of most pediatic and a good amount of adult patients
  • Other causes: strept, pneumo, staph

• epidemiology- mainly in children
• clinical features
  • fever, irritability, dysphonia, dysphagia, sore throat
  • on exam, pt sitting up, drooling
  • respiratory distress and inspiratory stridor may be present
  • may have a very rapid course

• direct visualization under anesthesia- edematous red epiglottis
• lab findings- leukocytosis, positive cultures of blood and epiglottis
• sometimes evidence of pneumonia
• radiograph of lateral neck- enlarged epiglottis

• maintain adequate airway
• in children, insert endotracheal or nasotracheal tube is recommended
• antimicrobial therapy direct against H. influenza
  • ex: ampicillin-sulbactam, cephalosporins
• us px in household contacts who are less than 4 yrs old

• definition
  • age specific viral infection, producing subglottic area inflammation, resulting in dsypnea and characteristic inspiratory stridulous sound
• etiology
  • most common: parainfluenza type 1,3
  • others
    • parainfluenza 2
    • influenza
    • RSV
    • rhinovirus
    • enteroviruses
    • Mycoplasma pneumonia

• viral infection produce inflammation of nasopharynx
• infection spreads to larynx and trachea, and then to lower tract
• obstruction is greatest at subglottic area, the least distensible part of airway
• impeded flow of air results in characteristic sound

• epidemiology- children 3-36 months
• clinical manifestation
  • URI symptoms usually precede
  • begin with hoarseness and cougph, proceeds to tachypnea, stridor
  • hypoxemia and hypercapnea may occur
  • some children have repeated episodes aka spasmodic croup (not that they have parainfluenza, but they react to infections the same way)

• characteristic clinical picture
• lateral neck radiographs reveal subglottic swelling steeple sign
• serologic dx is retrospective
• viral isolation from throat, tracheal, nasal wash specimens
• hear a seal barking sound

• supportive: follow pulse oximetry, in severely ill patients, follow P_CO2
• supplemental oxygen
• nebulized epinepherin to reduce subglottic inflammation
• systemic corticosteroids
• children may require intubation

• canal is narrow, trapping fluid and foreign objects
• this causes maceration of superficial tissues
• causative organisms
  • staph
  • strep
  • rare- pseudomonas

• clinical features
  • usually occur as result of pustle or furnucle due to Staph
  • group A strep can cause erysipelas of canal
• tx- systemic antibiotics and drainage may be necessary

• epidemiology- hot, humid summers
• clinical features
  • canal become edematous and red
  • gram negative rods (esp. Pseudomonas can play a significant role)
• tx- with ear drops of topical antibiotics and steroids

• clinical features
  • severe necrotizing infection that spreads from squamous epithelium to adjacent soft tissue, bv's, cartilage, bone
  • usually affects elderly, diabetics
  • usually caused by Pseudomonas aeruginosa
• tx- requires long course of systemic antibiotics

• highest incidence 6-24 mnths of age
• vast majority of kids affected have no anatomic defect
• there is likely genetic susceptibility
• age at first episode strongest predictor of recurrent infections

• S. pneumonia (most common)
• H influenza
• Moraxella catarrhalis
• Mycoplasma pneumoniae- hemorrhagic bullous myringitis
• viruses
  • rhinovirus
  • RSV
  • influenza
  • enterovirus

• dysfunction of physiologic functions of eustachian tube plays a critical role
  • inadequate drainage into the nasopharynx of middle ear secretions
  • inadequate equilibrium of air pressure with that of external ear canal

• ear pain, drainage, hearing loss, fever, lethargy
• tympanic membrane erythema and fluid in middle ear by pneumatic otoscopy
• fluids may persist for prolonged peroid

• direct antibiotics against likely pathogen (ex: amoxicillin-clavulanate, macrolides)
• surgical management, prevention
  • myringotomy
  • adenoidectomy
  • placmenet of tympanostomy tubes

• may be viral
• half of causes due to Strept pneumo and H. influenza
• anaerobic bacteria usually assoc. with dental disease
• nosocomial sinusitis: Staph and gram negatives
• immunocompromised host- gram negatives and fungi

• thought to be bacterial complication of viral colds
• colds can cause reversible abnormalities of sinus cavities
• sinus mucosal lining becomes inflammed and swollen
• exudate develops containing bacteria and leukocytes

• purulent nasal and postnasal discharge, pressure over sinus areas of face, headache, nasal obstruction, fever
• infection can extend to bone or intracranially
  • proptosis
  • limited EOM
  • meningitis
  • brain abscess
• exam pts may have tenderness overlying the sinuses, abnormal sinus transillumination

• clinical history and exam
• sinus CT scans
• sinus radiographs
• sinus puncture with cultures of exudate ffor severely ill patients not responding to antibiotics

• empiric antibiotics directed against suspected pathogens (S. pneumo, H influ)
  • amoxicillin-clavulanate
  • cephalosporins
  • extended spectrum fluoroquinones
• immunocompromised host or hospital acquired sinusitis, consider tx Pseudomonas

• definition- inflammatory condition of tracheobronchial tree associated with a respiratory infection
• etiology
  • common cold viruses
  • influenza
  • adenovirus
  • rarely nonviral cause
    • M. pneumoniea
    • C. pneumoniae
    • B. pertusis

• cough, preceded by nasal and pharyngeal complaints, fever may be present
• sputum production reported half the time, can be purulent in later stages, cough is prolonged in smokers
• with tracheal involvement, there may be substernal chest pain

• dx- clinical history and exam
  • if cough persists, consider CXR
• tx- symptomatic
  • cough suppressants

• definition- productive cough on most days during at least 3 consecutive months for more than 2 consecutive yrs
• etiology/epi
  • important contributing factors
    • smoking
    • infection
    • inhalation of irritants
    • diseases that impair host defenses
      • ex: CF, IgA or IgM sublcass deficiencies

• significant increase in number of goblet cells lining the surface epithelium of major and minor bronchi
• mucous glands in walls of larger bronchi hypertrophy
• irritated airways respond by producing extra secretions, aggravating cough and promoting bronchospasm

• epidemiology- mainly older adult males over 40 who smoke and often have COPD
• clinical presentation
  • incessant, productive cough, worse in morning
  • infection can induce acute exacerbation with increased, purulent sputum production

• dx- clinical history
• tx
  • smoking cessation
  • consider sputum analysis, if eosinophils present, investigate allergic component
  • pulm. function test to assess need for bronchodilators
  • pts with concomitant COPD- corticsteroids
  • antibiotics for acute exacerbations directed against H. flu and Strep pneumoa
    • Amoxicillin-clavulanate
    • cephalosporins
    • macrolides
    • expanded spectrum quinolones