Head and Neck Infections Flashcards
Term
Definition
What are the most common viruses that cause pharyngitis?
Adenoviruses (pharyngoconjunctival fever), influenza, cold viruses (rhinoviruses, coronaviruses)
What is the most common bacteria that causes pharyngitis?
Streptococcus pyogenes
What are the most common viruses that cause otitis media?
RSV, rhinoviruses, adenoviruses, influenza
What is the most common bacteria that causes otitis media?
Streptococcus pneumoniae
What is a common infection that is a complication of untreated otitis media? What bacteria causes this infection?
Mastoiditis, where the air cells are infected, usually by H. influenzae
What are the most common bacteria that cause sinusitis?
S. pneumonia, H. influenzae, M. catarrhalis
What is one of the most serious common complications of sinusitis?
Orbital cellulitis caused by Streptococcus spp., usually S. aureus and S. pneumonia; bacteria, because of edema, are able to move through the lamina papyracea (the thin bones separating the sinuses and orbit)
What structures make up the URT and the LRT?
Division is vocal vords; upper respiratory tract (URT) is the nasal cavity, nasopharynx, oropharynx, larynx; lower respiratory tract (LRT) is the trachea, bronchi, bronchioles, lung
Name the syndrome and most common viruses infecting the nasal cavity.
Rhinitis (common cold); rhinovirus, coronavirus
Name the syndrome and most common viruses infecting the nasopharynx, oropharynx, or larynx.
Pharyngitis (sore throat) or laryngitis; adenovirus or parainfluenza virus
Name the syndrome and most common viruses infecting the trachea or bronchi.
Laryngotracheobronchitis (croup); parainfluenzavirus; common in children, listen for the barking cough
Name the syndrome and most common viruses infecting the bronchi.
Brochitis; parainfluenza virus, influenza, adenovirus, metapneumovirus, RSV, coronavirus; watch for heavy productive cough with purulent sputum
Name the syndrome and most common viruses infecting the bronchioles.
Brochiolitis; RSV, influenza, metapneumovirus, adenovirus; very severe in infants because of small bronchiole size
Name the syndrome and most common viruses infecting the alveoli.
Pneumonia; (all respiratory viruses) influenza, rhinovirus, parainfluenzavirus, metapneumovirus, RSV, SARS, MERS, coronavirus, adenovirus
How are bacterial and viral respiratory pneumonias distinguished radiographically?
CXR shows viral pneumonias to be diffuse and bilateral while bacterial pneumonias are more focal with demarcated areas of opacity representing filled alveoli
Which respiratory viruses are RNA and which are DNA?
All are RNA except for adenoviruses
Describe the seasonality of respiratory viruses.
Most peak in the winter (e.g. RSV), except for parainfluenzavirus (late fall) and adenovirus (year round)
Describe the Baltimore classification, the family, and the structure of the rhinovirus.
(+) sense RNA virus; Picornaviridae; naked capsid
Describe the Baltimore classification, the family, and the structure of the coronavirus.
(+) sense RNA virus; Coronaviridae; enveloped, which makes it susceptible to detergents; includes SARS and MERS
Describe the Baltimore classification, the family, and the structure of the adenovirus.
dsDNA virus; Adenoviridae; naked capsid, but can survive and invade the GI tract through its binding of tight junction proteins
Describe the Baltimore classification, the family, and the structure of the parainfluenzavirus.
(-) RNA virus; Paramyxoviridae; buds out of the apical cell so it doesn’t cause cell lysis, but the increased epithelial turnover causes swelling
Describe the Baltimore classification and the family of RSV.
(-) RNA virus; Paramyxoviridae;
What are the two important surface proteins of RSV?
G-protein attaches to host and F-protein fuses the viral envelope to the host cell membrane
How does RSV evade the immune system?
The glycosylation of G-protein is hard for Ig to bind to, and soluble G-protein consumes Ig; RSV also infects DCs, hampering the immune response
What are the common clinical manifestations of adenovirus?
Pharyngitis, laryngitis
What are the common clinical manifestations of parainfluenzavirus?
Laryngotracheobronchitis, croup (look for the steeple sign, or subglottic stenosis on the radiograph)
How does RSV cause bronchiolitis?
Increased vascular flow, permeability, and mucus production after respiratory epithelial cell infection causes tachypnea, cough, respiratory distress with retractions, and wheezing
Which major virus is most similar to metapneumovirus?
RSV
