Upper Respiratory Tract Infections Flashcards
Pharyngitis causes:
Usually viral (rhinovirus or coronavirus). May result from group A streptococcus, or atypicals. Most important to identify STREPTOCOCCAL pharyngitis.
Viral pharyngitis signs and symptoms:
Nasal discharge
Sore “scratchy” throat
Non-productive cough with post-nasal drip
Red nares with clear discharge
Mucous on posterior pharyngeal wall, but no exudate.
No or minimal fever
Viral pharyngitis transmission:
Usually hand-to-hand (for rhinovirus), but others via aerosol
Virus may persist on fomites for several hours
Saliva is not an efficient means of transmission
Viral pharyngitis pathophysiology and recovery:
Most symptoms due to immune response
Clinical recovery is most likely due to interferon release by the nasal epithelium
Physiological stress is correlated with cold infection
Viral pharyngitis treatment:
Intranasal ipratropium bromide (reduces nasal discharge)
Ibuprofen/warm saline gargles
Antitussives (dextromethorphan, guiafenesin, or codeine)
Avoid aspirin use in children due to possibility of Reye’s syndrome
Viral pharyngitis complications:
Sinusitis
Acute otitis media
Lower respiratory tract disease
Group A strep pharyngitis signs and symptoms:
Abrupt onset Severe sore throat, pain with swallowing Systemic illness with feverishness and malaise Nasal congestion and cough (only in 50%) Temperature 100-104 Diffuse redness of pharynx and tonsils Tonsillar exudates (patchy or confluent) Enlarged, tender anterior cervical nodes
Group A strep pharyngitis diagnosis:
Important to prevent sequelae such as rheumatic fever.
If tonsillar exudates, enlarged tender cervical lymph nodes and temperature >100 are present, there is a 42% chance of the patient having the infection.
Culture on blood agar
Rapid enzyme immunoassay
Group A strep pharyngitis treatment:
Begin antibiotics (oral penicillin V) within 9 days of symptoms to prevent rheumatic fever. Erythromycin or another macrolide in individuals allergic to penicillin.
Infectious mononucleosis signs and symptoms:
Exudative pharyngitis/laryngitis Fever, headache, malaise, and fatigue Onset: abrupt or with several day prodrome Diffuse cervical adenopathy Splenomegaly in 50%
Infectious mononucleosis etiology:
Usually EBV. May be CMV, HIV, and toxoplasma.
Persists in oropharynx for 18 months after clinical recovery
Infectious mononucleosis diagnosis:
Hematological findings include atypical T-cells on peripheral smear.
Thrombocytopenia in 50%.
Positive heterophile antibody test with EBV
Influenza signs and symptoms:
Abrupt onset
Systemic symptoms predominate (headache, high fevers, myalgias)
Pharyngitis is minimal.
Small, tender, cervical adenopathy common
Influenza pathogenesis and etiology:
Influenza A and B virus
Transmitted by aerosol droplets (1 day prior to onset to 5-10 days after resolution of fevers)
Interferon is active in the recovery process before the serum or secretory antibody is detected.
Influenza diagnosis:
Clinical diagnosis in setting of epidemic has high PPV
Rapid assay (ELISA) on nasopharyngeal aspirate
Nasal or throat swab
Influenza treatment and prevention:
Supportive. Amantadine/rimantadine reduce symptoms by 50%, neuraminidase inhibitors (oseltamivir/zanamivir).
Vaccine has 80-90% efficacy.
Acute bronchitis:
An acute inflammatory condition of the tracheobronchial tree that does not involve the pulmonary parenchyma.
Acute bronchitis signs and symptoms:
Persistent cough for days, +/- sputum production, +/- fevers, lung exam reveals crackles and wheezes, but no consolidations.
Acute bronchitis causes:
Usually viral (rhinovirus).
Mycoplasma pneumoniae and Chlamydia pneumoniae are common.
Bordatella pertussis is relatively rare.
Mycoplasma bronchitis symptoms:
Cough (dry and hacking at first, followed by production of mucoid sputum, then purulent sputum). Usual duration is 2 weeks.
Rhonchi and coarse rales commonly heard on lung exam. Low grade fever.
Wheezes may be induced, most commonly in atopic or asthmatic individuals.
Bronchitis diagnosis:
Important to distinguish from pneumonia.
Patients with pneumonia are usually more ill.
Chest radiography will reveal either nothing or peribronchial cuffing with bronchitis, but an infiltrate is usually present with pneumonia.
Serum IgM immunoassay is useful for M. pneumoniae.
Bronchitis treatment:
Treat cough symptomatically with dextromethorphan or codeine.
Bronchodilators or steroids for wheezing.
Erythromycin or another macrolide for M. pneumoniae or C. pneumoniae.
Acute sinusitis:
Infection of one or more of the perinasal sinuses. May be viral, bacterial, or fungal.
The sinuses are lined with ciliated, pseudo-stratified epithelium which is covered by a thin mucus blanket. The sinuses are sterile under normal conditions, even though there is a direct connection to the nasopharynx.
Sinusitis results from obstruction of the ostia during a viral URI.
Acute sinusitis causes:
Streptococcus pneumoniae
Haemophilus influenza