Nematodes, Cestodes,
Trematodes
Slackers Facts by Mike Ori
Disclaimer
The information represents my understanding only so errors and omissions are
probably rampant. It has not been vetted or reviewed by faculty. The source is our
class notes.
The document can mostly be used forward and backward. I tried to mark
questionable stuff with (?).
If you want it to look pretty, steal some crayons and go to town.
Finally…
If you’re a gunner, buck up and do your own work.
What are the physical causes of sinusitis?
Obstruction of airflow due to rhinitis or
mechanical obstruction
What are the acute sinusitis pathogens
Streptococcus pneumoniae
Moraxella catarrhalis
Haemophilus influenzae - unencapsulated
What is the cause of chronic sinusitis?
Staphylococcus aureus
Anaerobes
Enteric gram negatives
What are the complications of sinusitis
Intracranial extension (brain abscess)
Orbital infection
Osteomyelitis
What is the most common site of sinusitis
Maxillary sinus
What is the most benign site of sinusitis
Maxillary sinus
What are the agents of otitis media
Streptococcus pneumoniae
Moraxella catarrhalis
Haemophilus Influenzae
What are the agents of otitis externa
Pseudomonas aeriginosa
Enterobacteraciae
Fungi
What is the physical cause of otitis externa
Disruption of cerumen
Elevated pH
Trauma
What is the treatment for otitis media
Systemic antibiotics
Typanocentesis
Typanostomy
What are the treatments for otitis externa
Remove purulent material
Acidify canal with alcohol and acetic acid
Topical antibiotics if needed
Distinguish otitis media and otitis externa
OM: Usually no pain when pulling pinna.
Erythema and bulging seen on tympanic
membrane. Fluid level seen sometimes. No
discharge unless tympanum is perforated.
OE: Pain on pinna pull. Discharge often
present. Erythema, purulence on external
structures.
What are the agents of pharyngotonsilitis
Streptococcus pyogenes (GAS)
Respiratory viruses
Enteroviruses
EBV
Corynebacterium diphtheriae
Neisseria gonorrhea
What are the general complications of
phrayngotonsillitis
Abscesses
Obstructed airway
What are the agents of
Laryngotracheobronchitis
Parainfluenza
Other URI viruses
Mycoplasma pneumoniae
What is the common name for
Laryngotracheobronchitis?
Croup
What are the treatments for
Laryngotracheobronchitis
Protect airway if threatened
Humidified air
Racemic epinephrine
Corticosteroids if severe
What are the agents of epiglottitis
HIB in unvaccinated
Streptococcus pyogenes
Staphylococcus aureus
Why precautions must be taken when examining
the epiglottis
Airway protection must be available as reaction
to the examination may cause sever
constriction of the airway.
What is blepharitis?
Infection of the eyelid margin
What typically causes blepharitis
Staph aureus
What is dacryocystitis
Inflammation of the lacrimal sac
Is conjunctivitis sight threatening
Not usually
What is keratitis
Corneal infection
What are the viral agents of keratitis
HSV-1
VZV
Is keratitis sight threatening
Yes
What is uveitis
Infection in the iris, ciliary body, choroid
Is uveitis sight threatening
Yes
What are the agents of retinitis
CMV – in aids
Toxoplasmosis
Is retinitis sight threatening
The retina seems important.
What is endophthalmitis
Infection of the eye in general
(Requirement fo multiple structure
involvement?)
How are agents introduced in endophthalmitis?
Endogenously from hematogenous spread
Exogenously – trauma, surgery
What is the most common organism for
endogenous endophthalmitis?
Candida albicans
Is endophthalmitis site threatening
Yes
What is preseptal cellulitis
Infection of the face and eyelid anterior to the
orbital septum
Is preseptal cellulitis site threatening
Not usually
What is orbital cellulitis?
Infection of the structure surrounding the eye
Is orbital cellulitis site threatening
Yes. It is also conveniently life threatening. A
two-fer.
What fungal infection leads to orbital cellulitis?
Zygormycosis
Distinguish preseptal and orbital cellulitis
Preseptal can look awful in comparison to
orbital as the infection is often more obvious.
Eye movement is intact. Eye pain and
proptosis are absent.
Orbital: Often misleadingly mild appearance.
Pain, decreased motility, proptosis present.
Where does orbital cellulitis arise?
Often in the ethmoid and frontal sinuses
What is impetigo
An infection of the epidermis
What are the agents of impetigo
Streptococcus pyogenes
Staphylococcus aureus
Distinguish staph and strep impetigo
As a ballpark, staph is bullous and nonconfluent. Strep non bullous and confluent.
What is a non-complicated UTI
One in involving the bladder without retention
of urine
Describe the age and gender distribution of UTI?
F > M until later in life.
Old > young until death (at which point
incidence is harder to track)
Why are infections in men often “complicated”
BPH leads to urinary retention
What is the leading agent of UTI
Escherichia coli
Why is diabetes a risk for UTI
Increased glucose in urine
Neurogenic bladder due to neuropathy
Describe the epidemiology of osteomyelitis
Most cases < 13 yo
50% < 5 yo
Why is osteomyelitis more prevalent in children
The metaphyseal plates can form micro necrotic
(?) zones in which bacteria can lodge
In what types of bones does osteomyelitis tend
to occur
Long bones (ones with metaphyseal growth)
It tends not to occur in the flat bones
What are SX of osteomyelitis
Localized pain (possible favoring)
Point tenderness to palpation
Heat, redness, swelling develops over time
Often vague complaints with systemic sx like
fever
When do X rays become positive
At best 2 weeks after the infection has started.
What is the best imaging modality
MRI
What imaging modality is used if the site of
infection is unclear
Technitium-90 bone scans
What inflammatory markers are used in the dx
of osteomyelitis?
ESR
CRP
Do you follow ESR or CRP
ESR. Treat until it returns to normal
(approximates normal).
Describe the typical osteomyelitis tx duration
Typically tx continues for several weeks.
How is TX of a puncture wound to the foot
managed
If osteomyelitis occurs then surgical
debridement is necessary. ABX follow for 1
week typically.
How does septic arthritis occur
Most often hematogenous
Trauma
Some (16%) extend from osteomyelitis
What are the common sites of septic arthritis
Large joints like knee and elbows
Describe the distribution of septic arthritis
Typically single joint involved
Polyarticular tends toward collagen vascular
diseases
What is unique about the septic arthritis of the
hip
Inflammation in the capsule can lead to
diminished blood flow and necrosis of the
head of the femur. Recall that the femur has
limited vascularization paths.
What is the most common osteomyelitis and
septic arthritis agent
Staphylococcus aureus
What is the most common poly arthritis agent in
sexually active young people
Neisseria gonorrhea
When is a child a neonate
0-28 days
Describe the humoral immunity of neonates
Transplacental IgG (~23d T ½)
IgA from breast milk
What are the TORCHeS organisms
Toxoplasmosis
Other (viral)
Rubella
CMV
Herpes
Syphilis
Describe the role of TORCHeS in clinical practice
It is a hand mnemonic but not a definitive guide
What is the most common congenital infection
CMV
Approximately how many cases of rubella occur
in the US
~0
When should a woman of child bearing years be
vaccinated for rubella
Preferably before child bearing years to avoid
any possibility of congenital rubella due to
reactivation of attenuated rubella. Vaccinate
before leaving the hospital after delivery
How does post partum vaccination protect the
neonate
It doesn’t. Post partum vaccination protects
their future siblings.
What are the sx of congenital rubella
Triad: Heart defects, ocular defects (cataracts),
sensorineural deafness, celery stalk long
bones
How can you distinguish prior maternal infection
from congenital infection
Maternal ab are IgG. Neonatal are IgM
What are the agents of meningitis in neonated
E. coli, Group B strep, listeria
How is toxoplasmosis infection acquired
1. Cat litter
2. Under cooked meat (gato tacos?)
What are the sx of congenital toxoplasmosis
Microcephaly, cerebral calcification,
hydrocephaly, chorioretinitis
More in notes
What are the sx of congenital CMV
Organomegally, small for gestational age,
purpura, hepatitis, prolonged jaundice,
blueberry muffin rash, periventricular
calcification
How many infected children are asymptomatic
90%
What percent of herpes carriers are
asymptomatic
75%
What is the mortality rate of congenital herpes
60%
What are the classifications of congenital herpes
1. Skin-eye-membrane – herpetic lesions on
skin
2. CNS – Meningoencephalitis without skin
manifestations
3. Disseminated – encephalitis, pneumonia
What is the role of acyclovir in congenital herpes
prevention
Essentially no role
Which is the preferred delivery route?
C-section if lesions are noted.
When is congenital syphilis acquired
From the 4th month onward
What are the congenital syphilis symptoms
Saber shins, saddle nose
Rash
More in notes
Describe what tests are required to confirm
syphilis
Non-treponemal tests (RPR or VDRL) followed by
treponemal tests (FTA, MHA) if positive