Viral exanthems Flashcards
Virus causing Rubeola (type, family)
measles virus
RNA
paramyxovirus
Describe presentation rubeola (measles)
prodrome of fever and 3Cs (coryza, cough, conjunctivitis)
then morbilliform eruption *starts on frontal hair line/post auricular areas. Cephalocaudal spread
Koplik spots: gray-white papules on buccal mucosa and may resolve prior to onset of rash
Complications of measles
myocarditis
encephalitis
SSPE (subacuse sclerosing panencephalitis; occurs years after infection)
Treatment for measles
Vit A supplementation measles vaccine (given w/in 3 days of exposure)
When are kids immunized against measles?
2 doses at 12 -15 months and 2-4 years
How does rubella differ from measles (rubeola)
shorter and milder course; painful LAD
TORCH infection
Forcheimer’s spots
palatal petechiae a/w rubella
Virus causing erythema infectiousum
parvo B19
ssDNA
lab abnormality a/w parvo and pathophys
low Hgb; virus is tropic to bone marrow and replicates in RBC precursor cells –> causing transient anemia
** can cause aplastic crisis and pancytopenia in pts with pre-disposing conditions (i.e. sickle cell or other hemoglobinopathies)
presentation of parvo
prodrome of fever, myalgias, headache followed by exanthema 1-2.5 weeks later (no longer viremic/contagious when rash occurs)
- slapped cheek rash (erythema of cheeks that spares central face
- lacy, reticulated morbilliform rash favoring extremities
- **a/w arthralgias w/ small joint predominance(MC in adult); not infectious at this stage
parvo infection effects on fetus
**highest risk if aquired before 20 weeks
hydrops fetalis
anemia
high output heart failure
what is papular purpuric gloves and socks syndrome? and who gets it?
symmetric edema and erythema of palms and soles (may extend onto dorsal surface) due to parvo B19
a/w petechia and purpura with sharp demarcation at wrists and ankles
Young adults get it
**unlike erythema infectiousum, pts are viremic when they have rash
What virus causes exanthem subitum
HHV-6A and HHV-6B
DNA virus
who gets exanthem subitum
2-24 mo; MC in spring
presentation of exanthem subitum
very high fever for up to 5 days (+/- URI and LAD) - common cause of febrile seizures
Fever resolves as morbilliform eruption begins (favors trunk)
**benign course without sequelae
what are nagayama’s spots
red macules on soft palate and uvula
virus implicated as pathogenic factor in development of DRESS? why?
HHV-6 (exanthem subitum)
virus remains latent in CD4 T cells (can be re-activated)
virus causing HFM, seasonality?
coxsackie A16 (lesser extenent A6 and enterovirus 71) summer/fall
how is HFM tranmitted
fecal/oral and respiratory
presentation of HFM
- vesicular eruption MC involving palms/soles/buttocks and oral cavity
- erythematous macules and ovals with deep seated vesicles with bullae and gray center
- oral lesions can be erosive
Coxsackie A6 is a/w with what diseases?
HFM
eczema cosackium
gianotti crosti
onychomadesis
another name for gianotti-crostii syndrome
papular acrodermatitis of childhood
who gets gianotti-crostii
peak age 1-6 yo
seen after viral infection or sometimes vaccinations
MC virus a/w gianotti-crostii (in US vs worldwide)
EBV in US
Hep B worldwide
presentation of gianotti crostti
1-6 yo kid with symmetric, monomorphic skin colored to erythematous papules favoring cheeks, extremities and buttocks (sparing of chest, back, abdomen)
** takes 1-2 months to resolve
presentation of unilateral laterothoracic exanthem (aka asymmetric periflexural exanthem of childhood)
1-5 yo kids (usu female, usu spring) with UNILATERAL erythematous macules and papules beginning in axilla and lateral trunk (STATUE of LIBERTY SIGN)
resolves spontaneously in 3-6 weeks
chronic/recurrent C albicans infections of skin/hair/nails (thrush, perleche, chronic paronychia, diaper derm/intertrigo, dental enamel hypoplasia) is cuased by what genetic mutation and a/w what syndrome
AIRE gene (mut causes failture of R cell tolerance with resultant autoimmunity)
APECED = autoimmune polyendocrinopathy candidiasis-ectodermal dystrophy syndrome
Also def in IL-17
Features of APECED
autoimmune (AA, vitiligo)
polyendocrinopathy (hypoparathyroidism)
candidiasis
ectodermal dystrophy syndrome (dental enamel hypoplasia)
pernicious anemia
