infectious disease- 12% Flashcards
where is the MC pathogen that causes mycobacterium avium (MAC) complex found
M.avium; soil + water
what are the sx of MAC
rarely sx unless immunocompromised
lymphadenitis in kids- cervical + submandibular/maxillary
dx of MAC
acid fast bacillus stain + cx
tx of MAC
clarithro + ethambutol x12mo
what causes leprosy
LONG EXPOSURE to M.leprae- affects superficial tissues (esp skin + peripheral nerves)
where is M.leprae endemic
tropical areas
incubation period for M.leprae
months - 20-50yrs
presentations of leprosy
lepromatous
tuberculoid
mononeuritis multiplex
lepromatous disease
nodular, plaque or papular skin lesions (lepromas) w poorly defined borders, loss of eyebrows/eyelashes
symmetric nerve involvement (sensation preserved)
tuberculoid disease
limited; sharply demarcated hypo pigmented macular lesions numb to touch
mononeuritis multiplex disease
nerve damage:
clawing- median n + ulnar n
foot drop- common peroneal n
vibratory + proprioception preserved
what organisms cause pinworms
enterobius vermicularis
how are pinworms transmitted
feco-oral
dx of pinworms
scotch tape test in early AM
tx of pinworms
albendazole, mebendazole, pyrantel (2nd line); no tx in kids <2yo
what is EBV and how is it transmitted
HHV-4
saliva
what does EBV do
infects B cells
what type of cancer is EBV associated with
hodgkin lymphoma, burkitt’s lymphoma
who MC gets EBV
15-25yo
what are the sx of EBV
fever sore throat post cervical LAD malaise + myalgias spleno/hepatomegaly petechial rash (esp if given ampicillin)
how do you dx EBV
heterophile (monospot) Ab test
peripheral smear
inc LFTs
how long after infxn is monospot/heterophile Ab test positive for
up to 4wks
what is seen on peripheral smear of pt w EBV
> 50% lymphocytes w >10 atypical
how long should someone w EBV + splenomegaly avoid sports
1mo
what causes erythema infectiosum
fifth disease- parvovirus B19
how is parvovirus B19 transmitted
resp droplets
how long is the IP for parvovirus B19
4-14 days
in what age group is erythema infectiosum most common
<10yo
sx of erythema infectiosum
coryza, fever –> slapped check w circumoral pallor –> lacy reticular rash on extremities that spares palms/soles
arthralgia
how long does the slapped cheek rash last
2-4 days
tx of erythema infectiosum
supportive, resolves in 2-3wks
which pts with erythema infectiosum are at risk for aplastic crisis
sickle cell
G6PD deficiency
what is acute herpetic gingivostomatitis
1ry HSV infxn in kids- sudden onset of fever, anorexia –> gingivitis, vesicles in mouth, tongue + lips –> gray/yellow lesions
MC cause of encephalitis
HSV
tx of HSV
acyclovir
what is the most sensitive test for HSV
PCR
what type of virus is influenza
orthomyxovirus
which is worse- influenza A or B
A- more extensive + severe outbreaks
transmission of influenza
airborne
when do you give antivirals to flu pts and what are they
if high risk of complications
or w.i 48hrs
oseltamivir/tamiflu (PO)
when is flu vaccine CI
egg allergy
h/o GB/severe allergic rxn
what causes mumps and how is it spread
paramyxovirus - respiratory droplets
what is the incubation period for paramyxovirus
12-14 days
when is a pt with mumps infectious
2 days before + 9 days s/p parotid swelling onset
sx of mumps
low grade fever, myalgias, headache –> parotid gland swelling
what are the complications of mumps
orchitis, acute pancreatitis
MC in older pts
what might you see on labs in a pt w mumps
increased amylase
how long does mumps last
7-10 days
what causes roseola and how is it spread
HHV-6 or 7
respiratory droplets
how long is the IP for roseola
10 days
who MC gets roseola
<5yo
what is the presentation of roseola
prodrome high fever for 3-5 days –> fever breaks –> rose, pink maculopapular, blanchable rash on trunk/back –> face
how long does rash in roseola last
1-2 days
what causes rubella and how is it transmitted
rubella virus (togavirus) respiratory droplets
what is the incubation period of rubella
2-3wks
what is the presentation of rubella
low-grade fever, cough, anorexia, LAD (post cervical + auricular) –> pink, light-red spotted maculopapular rash on face –> extremities
forcheimer spots
transient photosensitivity + joint pain
what is the only childhood exanthem that starts on the trunk
roseola
MC diagnostic tool for rubella
immunoassay (IgM)
what can contracting during pregnancy cause
esp bad in 1st trimester congenital syndromes sensorineural deafness cataracts TTP (blueberry muffin rash) mental retardation heart defects (TORCH)
what causes measles, how is it spread and what is the incubation period
rubeola virus- paramyxovirus
respiratory droplets
10-12 days
prodrome of measles
URI prodrome- high fever, 3 Cs (cough, coryza, conjunctivitis) –> koplik spots
precedes rash by 24-48h, lasts 2 days
what is the rash of measles like
morbiliform brick-red rash on face beginning at hairline –> extremities
darkens + coalesces (lasts 7 days)
how does the measles rash go away
7 days
fades from top to bottom
what role does vitamin A play in measles tx
reduces mortality in ALL kids
complications of measles
diarrhea OM pneumonia conjunctivitis encephalitis
what causes varicella, how is it spread and what is the incubation period
HHV-3, respiratory droplets, 10-20 days
presentation of chicken pox (varicella)
fever, malaise, clustered PRURITIC vesicles on erythematous base in DIFFERENT STAGES
starts on trunk/face –> extremities
complications of varicella
bacterial infxn
encephalitis
GB syndrome
what kind of virus is coxsackie
enterovirus
how is coxsackie transmitted
feco-oral + oral-oral
what can both coxsackie A + B cause
aseptic meningitis
rash
common cold sx
what is hand-foot-mouth disease and how does it present
coxsackie
mild fever, URI, dec appetite –> oral vesicular lesions w erythematous haloes –> exanthem (vesicular macular or maculopapular lesions on distal extremities)
when is coxsackie most common
late summer/fall
what is herpangina and what causes it
coxsackie- type A
sudden onset
high fevers, stomatitis, sore throat lasting 3-5 days
what is the MC viral cause of pericarditis + myocarditis
coxsackie type B
what organism causes pertussis and how long is the IP
bordatella pertussis
7-10 days
in what age group is pertussis MC
<2yo
what are the 3 phases of pertussis + how long do they last + which is the most contagious
catarrhal 1-2wks; MOST CONTAGIOUS
paroxysmal 2-4wks
convalescent up to 6wks
what happens in the catarrhal phase of pertussis
URI sx for 1-2wks
what happens in the paroxysmal phase of pertussis
severe coughing fits w inspiratory whooping sound +/- post-jussive emesis
lasts 2-4wks
what happens in the convalescent phase of pertussis
resolution of cough
lasts up to 6wks
what causes scarlet fever
Type IV hypersensitivity rxn to pyrogenic GABHS infection
presentation of scarlet fever
fever, chills, pharyngitis
diffuse erythema that blanches w pressure
small papules (sandpaper rash) starting in groin/axillae –> trunk + extremities (spares soles/palms)
rash desquamates over time
flushed face w circumpolar pallor + strawberry tongue
pastias lines
what are pastias lines
linear petechial lesions @ pressure points
tx of scarlet fever
pen G or Vk (1st line)
macrocodes if PCN allergic
clinda or CPNs
when can pt w scarlet fever go back to school
24hrs s/p abx initiation
