Quiz 4 Flashcards
Define blepharitis:
Inflammation of the eyelid (hordeolum “stye” involves oil gland)
Define dacryocystitis:
Inflammation of the lacrimal sac (usually partial or complete obstruction)
Define conjunctivitis:
Inflammation of the conjunctiva (may extend to other parts of eye)
Define keratoconjunctivitis:
Extensive disease involving conjunctiva and cornea (may lead to ulceration, scarring, and blindness)
Define ophthalmia neonatorum:
Acute, sometimes severe conjunctivitis or keratoconjunctivitis of newborns
Define endophthalmitis:
Infection of aqeuous or vitreous humor
Define uveitis:
Inflammation of the uveal tract (iris, ciliary body, and choroid)
*most are not infectious origin
Define chorioretinitis:
Most common infective involvement of uveal tract (may lead to destruction of choroid and optic nerve inflammation)
Define chorioretinitis:
Most common infective involvement of uveal tract (may lead to destruction of choroid and optic nerve inflammation)
What are common infectious causes of blepharitis?
Staphylococcus aureus
What are common infectious causes of dacryocystitis?
Streptococcus pneumoniae
Staphylococcus aureus
What are common infectious causes of opthalmia neonatorum?
Neisseria gonorroeae
Chlamydia trachomatis
HSV
What are common infectious causes of endophthalmitis?
Staphylococcus aureus
Pseudomonas aeruginosa
*other gram-negative organisms
Candida spp.
Aspergillus spp.
What are common infectious causes of iridocyclitis?
Treponema pallidum
HSV
VZV
Where is the cutoff betweeon the upper and lower respiratory tract?
the glottis
Define lobar pneumonia. What organism is most likely (others also possible)?
Intra-alveolar exdate evolved into a consolidation
Streptococcus pneumoniae
Define bronchopneumonia:
Patchy distribution from bronchioles into adjacent alveoli of acute inflammatory infiltrates
Define atypical or walking pneumonia. What are likely pathogens?
Diffuse patchy infiltrates seen on interstitial areas of alveolar walls
Mycoplasma
Chlamydophila
Legionella
Viruses
Define aspiration:
The inhalation of either oropharyngeal or gastric contents into the lower airways
What is the main difference between aspiration pneumonia and aspiration pneumonitis?
Aspiration pneumonitis does not have an infectious etiology
Untreated aspiration pneumonia may progress to what specific disease condition?
Lung abscess- necrosis of pulmonary parenchyma with a collection of purulence
What are notable symptoms of a lung abscess? What are notable treatments?
Sx:
-Fever
-Productive cough
-Weight loss
-Diaphoresis
Tx:
-antibiotics w/ anaerobic coverage (should NOT use daptomycin)
-drainage/surgery
What is the difference between antigenic drift and antigenic shift as it pertains to the influenza virus? Which is responsible for influenza pandemics?
AD: Changes in H and N proteins due to genetic mutations in viral genome
AS: Two different strains infect same host and swap H or N proteins to create new strain
AS is responsible for pandemics
This CXR is a classic presentation of what kind of pneumonia? What major sx would be expected?
Bacterial pneumonia (CXR infiltrate)
Fever, productive cough, and dyspnea
What are the two distinct types of respiratory epithelium? Where is each type principally found?
-Stratified squamous epithelium (oropharynx and nasopharynx)
-Respiratory epithelium (paranasal sinuses, middle ear, respiratory tract below epiglottis)
Which type of respiratory epithelium is colonized with bacteria? Which type is sterile (more or less)?
Stratified squamous epithelium is colonized with bacteria
Respiratory epithelium is relatively sterile
What pathogen is most likely to cause rhinitis or rhinosinusitis? (Although many pathogens are possible candidates) Approximately what proportion of rhinitis is this pathogen responsible for?
Rhinovirus
50-60%
Patients diagnosed with sinusitis are not usually treated with abx with what three notable exceptions?
-Persistant sx w/ no improvement for 10 days
-Fever >102 F + facial pain/purulent nasal discharge for 3 days
-Second sickening- Abrupt worsening of sx after initial improvement
What treatments are recommended for sinusitis? If antibiotics are indicated which are preferred?
Acetaminophen, ibuprofen, decongestants, nasal steroids or nasal irrigation
Amoxicillin or amox-clav can be used but are not often indicated
Which fungi are most likely to cause allergic fungal rhinosinusitis? Which fungi are most likely to cause invasive fungal sinusitis?
Aspergillus spp.
Aspergillus spp. and mucormycetes
What is the treatment used for invasive fungal sinusitis?
Emergent/aggressive surgery, as well as azoles or amphotericin B
Is sinusitis more likely to be viral or bacterial in nature?
Viral (95%)
Which pathogens are most likely to cause otitis media?
Streptococcus pneumoniae
Haemophilus influenzae
Moraxella catarrhalis
Which pathogens are most likely to cause otitis externa?
Staphylococcus aureus
Pseudomonas aeruginosa
How is otitis media diagnosed? What are the pertinant signs? How is it commonly treated?
Clinical exam
Bulging and red tympanic membranes (in adults tympanic membrane may be retracted or bulging)
Tx:
-Mostly self-limiting (children >2yo may benefit from abx)
-If abx, usually amox or amox-clav for 5-10 days
What treatment is usually given for otitis externa? What patient population is at highest risk for malignant otitis externa (MOE)? What treatment is administered for MOE?
Tx w/ antibiotic drops
Elderly diabetics at highest risk for MOE
Tx:
Prolonged courses of IV abx
Approximately what percent of pharyngitis is viral? Which viruses are most likely?
30-60%
Rhinovirus > coronavirus > adenovirus
What are major symptoms of pharyngitis? How is it typically diagnosed?
Sx:
tonsillar exudate, fever, no cough, tender anterior cervical adenopathy
Dx:
-Rapid strep test (ELISA on Lancefield Group A carbohydrates)
What other notable bacteria besides GAS is a common cause of pharyngitis? What antibiotics may or may not be indicated in the best coverage of both bacteria?
Fusobacterium necrophorum
Azithromycin will NOT cover F. necrophorum, and should not be used for Tx of sore throat
What are two potential complications of sore throat?
Peritonsillar abscesses, which require immediate drainage and abx
Lemierre’s disease, which is an infected clot of the jugular vein
What other infectious pathology may appear similar to strep throat?
Mononucleosis (EBV infection), which can often present with abnormal liver tests and splenohepatomegaly
What are the Centor critiera? How are symptoms scored?
Fever
Tonsillar exudate
Tender anterior cervical adenopathy
No cough
Do all streptococci have a group? What is an example of a streptococci that cannot be grouped?
No
Streptococcus pneumoniae
What sign is visible on this x-ray? What is it suggestive of?
Thumb sign
epiglottitis
What are symptoms of epiglottitis? Though it is rare, what pathogen most commonly causes epiglottitis?
Severe sore throat with rapid progression to dysphagia and drooling
H. influenzae
*epiglottitis requires emergent evaluation
What sign is visible on this x-ray? What is it suggestive of?
Steeple sign
Croup (laryngotracheitis)
What is croup (laryngotracheitis)? In what age group is it most common?
Inflammation of the upper airway resulting in obstruction
6months to 6 years
What are major symptoms of croup?
Inspiratory stridor
Barking cough
Hoarse voice
Increased breathing work
Which viruses are the most common causes of croup?
Parainfluenza and rhinovirus
Also RSV, influenza, enterovirus
What are the available treatments for croup?
Steroids (all cases)
Inhaled epinephrine (if moderate to severe)
What are the two most common causes of bronchiolitis? During what seasons and which age demographics are most at risk?
RSV as well as rhinovirus
Fall or winter outbreaks are most common
Children under 2yo are most at risk
What are the common Sx of bronchiolitis? What Tx are used?
Sx:
Fever, cough, respiratory distress, wheezing crackles
Tx:
Supportive care
Of Influenza A, B, or C, which can be contracted by humans, birds and pigs?
Influenza A
What are the most direct results of damage to and sloughing of the respiratory epithelial cells caused by influenza?
Cough and pneumonia
What are common sx of an influenza infection? What are common diagnostic methods? What treatments are commonly used?
Sx:
Fever, aches and pains, fatigue, cough (due to immune response)
Dx:
-Rapid flu test (low sensitvity)
-RT-PCR (more sensitive, takes several hours)
Tx:
Oseltamivir/zamamivir
*resistance to oseltamivir is rare, but zamamivir usually works well in situations with resistance
What pathogens are associated with TORCH syndrome?
T- Toxoplasma gondii
O- Other (Treponema pallidum,VZV, LCM virus, Zika virus, Trypanosoma cruzi)
R- Rubella
C- CMV
H- HSV
Which TORCH infection is characterized by skin scarring, along with formation of a cicatrix?
Varicella zoster virus
Which TORCH infections are most strongly associated with hydrocephalus and chorioretinitis?
Toxoplasma gondii
Lymphocytic choriomeningitis virus
How is LCM virus transmitted?
Via rodent droppings
How is Zika virus transmitted?
Via mosquitos
Which TORCH infection is most characterized by microcephaly?
Zika virus
Which TORCH infection is most characterized by cataracts and congenital heart defects?
Rubella
Which TORCH infection is most characterized by sensorineural hearing loss and microcephaly?
Cytomegalovirus
Which two TORCH infections are the most common?
CMV
Syphilis
Which TORCH infections can be detected by PCR?
Zika virus
Rubella
CMV
HSV
Which TORCH infections can be detected by IgM assay?
Toxoplasmosis
Zika virus
Rubella
What diagnostic method can be used to detect Treponema pallidum?
RPR or VDRL (VDRL of CSF)
Why is testing for IgG antibodies in infants not done?
Infants do not yet produce IgG, so serum IgG is provided by the mother through the placenta or through breast milk
What are common hematologic disturbances in symptomatic TORCH infections?
Thrombocytopenia
Leukopenia
Anemia
Roughly what percentage of patients with cCMV are symptomatic?
10-15%
What is the #1 non-genetic cause of sensorineural hearing loss (SNHL) in children?
cCMV
What is the median age of onset of cCMV?
33 months
How can cCMV be diagnosed?
PCR on urine or saliva (saliva can give false positive if breastfeeding)
Which infants with cCMV should receive treatment?
All of them
What treatments should all cCMV receive?
-Regular auditory evaluation (most important)
-Careful monitoring of neurodevelopment
-Ophthalmologic evaluations
Which cCMV patients should be treated with ganciclovir/valganciclovir?
Patients with moderate-severe symptoms
What are good prevention practices for contraction of CMV?
-Hand hygiene
-Standard precautions
-Care around secretions from children (Saliva, urine, blood, etc)
What pathology is shown on this CXR? Which viral pneumonia-causing pathogen would be most likely to present with this finding?
Ground glass opacity
SARS-CoV-2
Which viral pneumonia-causing pathogen is especially notable for potential to cause multisystem inflammatory syndrome (MIS) in children?
SARS-CoV-2
What are appropriate early and late treatments for a SARS-CoV-2 infection?
Tx- early
-Remdesivir
-Nirmatrelvir
-Molnupiravir
Tx- late
-Steroids
-Tocilizumab
What three pathogens are most likely to cause typical community-aquired bacterial pneumonia?
S. pneumoniae (most common)
H. influenzae
M. catarrhalis
What is the function of the enzyme pneumolysin, which is produced by S. pneumoniae?
To destroy epithelial cells, increasing the inflammatory resposne
What is the appropriate treatment for typical community-acquired bacterial pneumonia?
Beta-lactam abx
What is the appropriate treatment for atypical community-acquired bacterial pneumonia?
Macrolides or quinolones
What are the three pathogens most likely to cause atypical community-acquired bacterial pneumonia?
Mycoplasma pneumoniae
Chlamydophila pneumoniae
Legionella pneumophila
What is significant about the lack of a cell wall in Mycoplasma pneumoniae? What additional substance gives stability to the cell membrane?
It is beta-lactam resistant
Sterols
What age group is at highest risk for a M. pneumoniae infection?
Children ages 5-15
How can a M. pneumoniae infection be diagnosed?
PCR (microscopy doesn’t work, neither do stains due to lack of a cell wall)
Which bacterial infection causing atypical pneumoniae usually presents with the most severe symptoms?
Legionella pneumophila
How many serotypes are tested for in the Legionella pneumophila urine antigen test?
1 serotype
Which two bacteria are most heavily associated with nosocomial infections, infections of ventilated pts, CF pts, and elderly pts?
P. aeruginosa
S. aureus
What type of pathology is visible on this CXR? What is the most common etiology? What are other things that belong on the ddx?
Focal opacity in LLL
Pneumonia (PNA)
Cancer and pulmonary embolism (PE)
What type of pathology is visible on this CXR? What things belong on the ddx?
Cavitary lesions
Septic emboli, cancer, TB (especially if in UL)
What type of pathology is visible on this CXR? What things belong on the ddx?
Diffuse ground-glass opacities
PE, ARDS, COVID-19, PJP, vaping
Mycobacteria possess a waxy coat which allows them to survive the phagolysosome effects in what principle cell type?
Inactivated (normal) macrophages
What the the two most notable virulence factors of M. tuberculosis?
Chording factor
Sulatides
What effect is achieved by the chording factor in M. tuberculosis?
Macrophages are activated -> granuloma formation -> release of TNF-a
What effect is achieved by the sulatides in M. tuberculosis?
Phagolysosome fusion is inhibited
Is TB airborne or droplet precautions?
Airborne (particles can last for several hours in the air)
What four drugs compose the first line treatment for TB infection? What is the main toxicity associated with these drugs?
R- Rifampin
I- Isoniazid
P- Pyrazinamide
E- Ethambutol
Hepatotoxicity
What is the MoA of Rifampin (RIF)? What unique side-effects does it present with?
RIF blocks DNA-dependent RNA polymerase
SE: Body fluid discoloration
Due to the many drug interactions of Rifampin, what drug can be used in its place?
Rifabutin
What is the MoA of Isoniazid? Why is pyridoxine given with treatment?
INH inhibits mycolic acid synthesis
To prevent deficiency leading to peripheral neuropathy
What is the MoA of Pyrazinamide?
PZA is converted to pyrazinoic acid and lowers intracellular pH
What is the MoA of Ethambutol? What unique side-effects does it present with?
EMB inhibits arabinosyl transferase
SE: Optic neuritis
Into what Runyon group does Mycobacterium marinum fall?
Runyon I- Photochromogens
How can a Mycobacterium leprae infection be diagnosed?
Skin biopsy or nasal mucosa scraping
What are the two types of leprosy associated with M. leprae?
Lepromatous leprosy
Tuberculoid leprosy
What are 3 facts that distinguish lepromatous from tuberculoid leprosy?
Lepromatous leprosy
-Poorly demarcated lesions
-Paresthesias
-Multibacillary
Tuberculoid leprosy
-Well demarcated lesions (also central hypopigmentation)
-Hypoesthesia
-Paucibacillary
During a TST test or an IGRA, how are macrophages involved in the immune response?
Macrophages bind the TB antigen and act as an APC, presenting it to CD4+ Th1 cells
What principle cytokine is released by Th1 cells after being activated by macrophages with the TB antigen?
IFN-gamma
What substance is used for NAAT of a Mycobacterium tuberculosis infection?
sputum
What is the name of the pathology shown here? What might they me indicative of?
Janeway lesions
Infective endocarditis
What is the name of the pathology shown here? What might they me indicative of?
Osler nodes
*they are painful
Infective endocarditis
What is the name of the pathology shown here? What might they me indicative of?
Splinter hemorrhage
Infective endocarditis
What are major risk factors for infective endocarditis?
Age (> 50yo)
Male
Structural HD or Rheumatic HD
IV drug use
Poor dentition/dental procedures
What is the mortality of untreated infective endocarditis? With treatment?
100%
25%
What are the three most common symptoms of infective endocarditis? (above 25% of pts)
Fever (96%)
New heart murmur (48%)
Hematuria (26%)
What are the two main tools used to diagnose infective endocarditis?
Echocardiography
Duke criteria
What are the two types of echocardiography used for diagnosis of infective endocarditis (IE)?
Transthoracic (TTE)
Transesophageal (TEE)
What are the pros and cons of using TTE or TEE to diagnose infective endocarditis?
TTE:
-Non-invasive
-Sensitivity for IE less than 60%
TEE:
-Sensitivity is greater than 90% for IE
What are the treatments for infective endocarditis?
IV antibiotics
*Repeated blood cultures every 24-48 hours are taken, as well as subspeciality consult team meetings
What are the risk factors for acute pericarditis?
Male
Age (20-50 yo)
What are major symptoms of acute pericarditis?
Pain that worsens when lying down (pericardial stretching)
Friction rub
Hypotension
Kussmaul sign (JVD)
Distant heart sounds
What EKG and CXR manifestations are consistant with acute pericarditis?
EKG: diffuse ST elevation
CXR: enlarged heart
What are common treatments for acute pericarditis?
-Symptomatic pain management (usually NSAIDs, but gluccocorticoids can be used if NSAIDs are CI)
-Abx/antifungals etc.
-Surgical drainage if contrictive
What are the two types of antigen reactions that are described as Type II hypersensitvity reactions?
What kind of skin infection is shown here? Is it purulent or non-purulent? What layers of skin are affected?
Impetigo
Non-purulent
Epidermis
Is this an example of flaccid or tense bullae?
Flaccid bullae
What is the skin infection pictured here? Is it purulent or non-purulent? Which layers of skin does it affect?
Ecthyma
Non-purulent
Epidermis and upper dermis
What is the skin infection pictured here? Is it purulent or non-purulent? What layers of skin does it affect?
Erysipelas
Non-purulent
Upper dermis
What is the skin infection pictured here? Is it purulent or non-purulent? What layers of skin does it affect?
Cellulitis
Non-purulent
Subcutaneous
What is the skin infection pictured here? Is it purulent or non-purulent? What layers of skin does it affect?
Folliculitis
Purulent
*Infection of hair follicle
What is the skin infection pictured here? Is it purulent or non-purulent? What layers of skin does it affect?
Cutaneous abscess
Purulent
Subcutaneous tissue
What is the skin infection pictured here? Is it purulent or non-purulent? What layers of skin does it affect?
Carbuncle
Purulent
*hair follicles, coalescence of several furuncles
What is the skin infection pictured here? Is it purulent or non-purulent? What layers of skin does it affect?
Hidradenitis suppurativa
Purulent
chronic recurrent, relapsing suppurative infection of apocrine and sebaceous glands
What two treatments can be used for most purulent skin infections?
Incision and drainage
Systemic antibiotics
What organisms is most likely to have caused the necrotizing fasciitis with the presentation pictured here?
Vibrio vulnificus
What is the name of the indicated cells on this histology slide? What infection are they characteristic of?
Henderson-Paterson inclusion bodies or molluscum bodies
Molluscum contagiosum
What four disease conditions have a strong association with HLA-B27?
Psoriasis
Ankylosing spondylitis
IBD
Reactive arthritis
