IDMM Week 3 PBL Flashcards
lesion
any abnormality involving any tissue or organ due to any disease or any injury
rash
a change in the SKIN which affects its color, appearance, or texture
primary lesion
initial lesion that characterizes a condition
secondary lesion
modification by regression or trauma of a primary lesion (i.e scab)
exanthems
skin rashes
eruptive epidermal lesions
enanthems
lesions on internal epithelial surfaces (i.e oral cavity)
what do macules look like
change in surface COLOR
no elevation or depression (NONPALPABLE)
ill defined
no change in texture
**1 cm or less
what can cause macular rashes
measles mumps rubella 5th disease CMV EBV dengue adenovirus
what does a patch look like
large macule
nonpalpable, maybe some wrinkle
**larger than 1 cm
what does a papule look like
circumscribed
solid ELEVATION
no visible fluid
**1 cm or less
what diseases can cause a papular rash
enterovirus
HPV (warts)
what does a plaque look like
broad papule
elevation, plateau like
**1cm
what does a nodule look like
similar to a papule but extends DEEPER
what does a vesicle look like
circumscribed
FLUID containing
ELEVATED
**less than 1cm
may have erythematous margins
what diseases can cause vesicular rashes
HSV 1/2
VZV
enterovirus
coxsackie virus
what does a pustule look like
it is a type of VESICLE
small elevation
contains CLOUDY/PURULENT material
**necrotic inflammation cells
what causes putstules
bacteria
what does a petechial rash look like
small hemorrhage beneath the epidermis
what causes petechial rash
coxsackievirus
rocky mountain spotted fever
N. meningitidis
what is an ulcer
CONVEX
discontinuity of skin
what is a blister
collection of fluid under the top layer of skin
can contain serum/plasma, water, pus, blood
what disease does the VZV virus cause
chicken pox
what does VZV infection/chickenpox look like
widespread VESICLES with red base appearing as “dew on a rose petal” rash
spreads CENTRIFUGALLY
what disease does HSV cause?
herpes
what does herpes infection look like
VESICULAR lesions in mouth/eye or genital/perianal regions
what diseases does coxsackievirus cause
herpangina
hand, foot and mouth disease
what does coxsackievirus infection look like
red oropharynx VESICLES
vesicles on h/f/m
what does smallpox infection look like
MACULES form first in the head then later in the extremities, becoming pus filled VESICLES then crusts
what does molluscum contagiosum look like
small pink skin tumors with central cimple often on trunk and anogenital regions
what does rubella infection look like
MACULOPAPULAR RASH
flate red area on skin covered by small pumps beginning in face and spreading to extremities
what does measles infection look like
starts at head and progresses to feet, disappearing in the order it appears
PALATAL PETECHIAE
what does infection with the human herpes viridae virus (HHV6) look like
causes “roseola”
in infants, is a rash on the trunk
what disease is caused by parvovirus B19
erythema infectiosum
what does parvovirus B19/erythema infectiosum infection look like
“slapped cheek” appearance
what disease causing rash is caused by GBS (S. pyogenes)
scarlet fever
what does scarlet fever look like
“sandpaper” rash
begins on trunk and spreads outwards
what disease is caused by R. rickettsii
rocky mountain spotted fever
what does R. rickettsii/rocky mountain spotted fever look like
MACULOPAPULAR rash on PALMS and SOLES spreading proximally to trunk
what disease is caused by R. prowazekii
epidemic typhus
what does typhus rash look like
spares palms, soles and face
what disease is caused by B. burgdorferi
Lyme disease
what does B. burgdorferi/lyme disease infection look like
erythema chronicum migrans
spreading annular RED LESION surrounding clear bite mark
what type of rash is characteristic of secondary syphilis
MACULOPAPULAR on palms and soles
what disease is cause by salmonella typhi
typhoid fever
what does typhoid fever rash look like
sparse rose spots and petechial lesions
mechanism of fever
fever is due to an elevated set point
- exogenous pyrogen binds to monocyte, macrophage or lymphocyte
- causes release of endogenous pyrogens (cytokines TNF alpha, IL1, IFN-gamma)
- endogenous pyrogens bind to endothelial cells near PREOPTIC HYPOTHALAMUS in leaky circumventricular organ (OVLT)
- endothelial cells synthesize prostaglandin E2 and NO
- PGE2 diffuses into preoptic hypothalamus and decreases the firing rate of warm sensitive neurons, increases the firing rate of cold sensitive neurons
- this increases the set point
which form of herpes can present as encephalitis in neonates
HSV2
which bacteria and viruses may cause meningitis in neonates
1.bacterial
E. coli
GBS
Listeria monocytogenes
- viral (more common)
enteroviruses
HSV
CMV
which bacteria and viruses can cause encephalitis in neonates
1. bacteria mycoplasma pneumoniae syphilis listeria TB salmonella typhi
2. viruses (more common) HSV measles mumps rabies arboviruses CMV
