81 Other viral diseases Flashcards
exanthem
def: eruption occurring as a sign of general disease
most common causes of nonspecific viral exanthems in children
non-polio enteroviruses (summer/fall); respiratory viruses such as adenoviruses, parainfluenza virus, and respiratory syncytial virus (RSV) (winter)
nonspecific exanthems tend to be …
self-limited, with spontaneous resolution in 1 week, and supportive therapy usually sufficient `
enteroviruses most common in …
summer and fall
list two enteroviruses
echovirus and coxsackie virus (a and b)
enterovirus incubation period
3-6 days
the quintessential enterovirus exanthem
hand-font-and-mouth disease; causes mainly by coxasakievirus A16
hand-font-and-mouth disease features:
vesicular eruption on the palms, soles, and an erosive stomatitis; dorsum of the hands/feet may also be involved as well as buttocks/perineum
onychomadesis
shedding of the nail plate at the proximal end (d/t temporary nail matrix arrest); seen in HFMD 1-2 after illness
strain of coxsackievirus associated with severe and atypical HFMD cases
coxasackievirus A6
herpangina
a ferile illness, primary in children 3-10 years of age; painful vesicles and erosions on the soft palate, uvula, tonsils, pharynx and buccal mucosa; exanthema usually absent; coxsackievirus A and B usual pathogen
HFMD (vesicular lesion) path
epidermal necrosis with intraepidermal vesicles, lack of inclusion bodies or multi nucleation, and nonspecific dermal inflammatory infiltrate
pleconaril
drug that interfere w enterovirus attachment and uncaring by binding to the protein capsid, may be beneficial in life-threatening enteroviral infections
measles synonym
rubeola
C’s of measles
cough, coryza, conjunctivitis, Koplik spots (gray white papule in buccal mucosa)
measles incubation, transmission, vaccines
10-14 days, respiratory droplets, two live vaccines (initial vaccine age 12-15 months and second at 4-6 years)
measles exanthema starts on … and spread in a … direction
on the forehead /hairline /behind the ears // cephalocaudad
viruses that causes morbilliform rashes
measles, enteroviruses, EBV, parvovirus B19, HHV-6; also drug eruption and Kawasaki’s
delayed neurodegenerative disorder that can occur as a completion of measles many years after acute disease
subacute sclerosing panencephalitis
measles treatment
vitamin A, supportive
rubella synonym; family of viruses
German measles; Togaviridae
rubella features
rose-pink macule with cephalocaudad spread, tender LAD (occipital and posterior auricular), joint involvement common, fetal infection a/w congenital anomalies
measles and rubella prodrome
fever, head, upper respiratory sxs (measles: also conjunctivitis)
rubella fading …
fades in 2-3 days in the same order as it appeared
congenital rubella syndrome features
cataracts, deafness, congenital heart defects (PDA, ventricular septal defects), and CNS abnormalities (microcephaly, developmental delay)
blueberry muffin baby presentation
feature of rubella, d/t dermal hematopoiesis
erythema infectiosum, synonyms
fifth disease, slapped cheek disease, parvovirus B19 infection
erythema infectiosum, features
slapped cheeks followed by lacy extremity-predominant eruption (children); petechial or aural/periflexural distribution (teens)
fetal B19 infection
anemia, fetal hydrops, death (mostly 2nd trimester)
B19 pathogenesis
has strong tropism for erythroid progenitor cells, and the erythrocyte P antigen (globoside), to which it binds –> this can lead to all sorts of cytopenias
B19 prodrome
fever, headache, muscle aches
B19 rash is exacerbated by …
heat /sunlight
syndrome a/w B19
papular-purpuric gloves and socks syndrome (PPGSS)
Roseola infantum, viruses
HHV-6 and sometimes 7
Roseola infantum, features
high fever follow by an exanthema at defervescence; mostly trunk and proximal limbs/neck
unilateral lanterothoracic exanthema
initial unilateral distribution (axilla/lateral trunk), with subsequent generalization (w unilateral predominance); presumed viral though unknown; typically lasts 3-6 weeks
Gianotti-Crosti syndrome
symmetric papular eruption (monomorphic) on the extremities, face, and buttocks, EBV (US) and HBV (globally) most common triggers; preceded by URI ; resolves in 3-6 weeks
most common pox infection in humans
molluscum contagiosum
most common host of cowpox
cats
orf
transmitted by sheep (think shepherds), coats, reindeer; papules (1 to few) on hands,; tx w/ imiquimod
list hemorrhagic fevers
zoonotic diseases: dengue, ebola virus, hantavirus, rift valley fever virus, yellow fever virus
dengue, features
biphasic fever, headaches, myalgia, N/V, retro-orbital pain; morbilliform or scarlitiniform rash with “white islands of in a sea of red”; also signs of bleeding: petechia, epistaxis, and gingival bleeding; severe dengue: plasma leakage –> shock/ respiratory distress/ hemorrhage
West Nile virus, features
culex mosquito and blood-product transmission, similar to dengue + LAD and encephalitis; rash predominates on the extremities
zika virus tranmission
Aedes aegypti and albopictus mosquito, sexual blood transfusion, and mother-fetus
zika infection, features
fever, arthralgias/arthritis, headache, conjunctivitis; cephalocaudad rash with follicular accentuation and palmar involvement; Guillain Barre has been reported
chikungunya
Aedes aegypti and albopictus mosquito, morbilliform eruption with acral or facial erythema and edema, and genital/intertriginous/oral ulcers; lots of PIH
Togaviruses endemic to Australia
Barmah Forest and Ross River Virus infections
hepatitis A cutaneous manifestations
panniculitis, urticaria, scarlet fever-like exanthema
hepatitis B and C cutaneous manifestations
see table 81.8 (lots of vasculitides, PAN, lived reticularis …
trichodysplasia spinulosa
polyomavirus; solid organ transplant recipients receiving immunosuppressive therapy; numerous erythematous to skin colored papules with a central spiny projection on the face, ears > extremities /trunk; alopecia of eyebrows /lashes; leonine facies; pat: large trichohyaline granules inside KC’s; improves w d/c of immunosuppressive therapy and antivirals
rabies and derm
dermatologist have been asked to do bx of nuchal skin to confirm dx
Kawasaki disease, features
fever, conjunctival injection, oral mucosal changes, acral swelling, and cervical LAD; polymorphous exanthema often with early perineal involvement
heart condition a/w Kawasaki
coronary artery aneurysms or ecstasias; myocarditis, pericardial effusions, CHF, valvular disease
peak times of the year for Kawasaki
late winter and early spring
leading hypothesis for pathogenesis of Kawasaki
bacterial toxin acting as super antigen, though not proven; but also evidence of virus-like particles within intracellular inclusion bodies in the ciliated bronchial epithelium of pts with KD
tx of Kawasaki
IVIG; ASA; some evidence for pulsed steroids and infliximab
