Infectious Exanthems Flashcards
DNA viruses
HPV - warts Pox virus - MC, smallpox (Variola) Orf virus - Exanthem contagiosum Herpes (varicella, HSV1/2, HHV 6/7, EBV) Parvovirus - erythema infectiosum (Fifth disease)
RNA viruses
Enterovirus (Coxsackievirus - HFM, Echo virus - non-specific, EV D68 - severe respiratory) Paramyxovirus - measles (rubeola) Togavirus - rubella arbovirus - dengue virus, chikungunya Filoviridae - ebola
exanthem
expressed on cutaneous surfaces
enanthem
expressed on mucosal surfaces
HPV –>
common warts, plantar warts, flat warts, genital warts, condylomata
HPV transmission
person to person by contact or through fomites
non-seasonal
HPV incubation
3 months to many years
HPV management
liquid N2, various acids, laser, surgical, laser
prevention
Small growth on surface of skin and gradually enlarges over long period. Relatively few sxs (maybe pain on foot). Small black dots seen centrally. Surface exhibits hyperkeratinization.
HPV - wart
Asymptomatic discrete papular waxy lesions gradually develop on surface of skin. Umbilicated appearance. 2-20 in generalized location
Molluscum contagiosum (poxvirus)
Molluscum contagiosum spread
humans - direct contact/fomites
non-seasonal
infectivity low
MC incubation
2-7weeks to 6 months
MC management
mechanical removal
liquid N2, acids
Vesiculated rash from distal distribution to central
HA, fever, malaise, muscular pains before rash
Rash develops in same stages w/ local crops and becomes encrusted. Illness lasts 2 weeks and resolves w/ significant scarring. Hemorrhagic form is highly fatal
Variola (smallpox) - poxvirus
Variola transmission
direct contact w/ skin lesions, mucous membranes
human transmission
animals in winter/spring
incubation smallpox
12 days
communicability of smallpox
onset of rash - clearing of crusts
dx of smallpox
culture of lesions, serology
smallpox management
strict isolation, symptomatic tx, active immunization
eczema vaccinatum
skin reaction - underlying skin disease + smallpox vaccine
Sheep herder (spring) notices small pimple on finger. No other sxs.
Ecthyma contagiosum, orf (poxvirus)
orf virus transmission
working with sheep - zoonosis usually seen in spring
directly from infected animal
incubation orf virus
4-7days
dx of orf
solitary lesion on hand, beginning as erythematous papule and developing into a vesicle
management of orf
duration is usually 30-40 days
spontaneously resolves w/ only symptomatic care
wear gloves
General malaise - fever - pruritic rash beginning centrally on head and trunk and extending peripherally.
Macule –> papule in 24 hrs
Local areas have various stages of development
Clears over week to 10 days
Latent infection, do not treat w/ aspirin (Reye’s)
varicella (chickenpox)
Herpes virus - VZV
VZV transmission
exposure to nasopharyngeal droplet, skin lesion contact, easily air spread
Peaks in late winter/spring
VZV incubations
14-16 days
VZV communicability
1-2 days before rash to when rash begins to crust (5 days)
VZV dx
clinical inspection of rash, spreading from macule to vesicles in 24 hours, hx of contact, immunofluorescence stain of lesion, serology
vzv management
strict isolation, avoid use of aspirin, avoid hospitalization, vitamin a, immunization
oral acyclovir w/in 24 hrs
smallpox vs chickenpox
smallpox ill 7-17 days after contact has fever/malaise 2-4 days before rash Pocks mostly on face/arms/legs Present on palms/soles Scabs 10-14 days after rash appears Fall off 14-28 days after rash appears
Chickenpox
ill 14-21 days after contact
no sxs before rash
pocks most numerous on body, not on palms/soles usually
Scabs 4-7 days after rash appears
scabs fall off w’/in 14 days after rash begins
Stinging erythematous lesion at junction skin/lip
Proceeds to crusted sore over few days but lasts up to 10-12 days. no systemic sxs noted.
Lesions of oral cavity (gingiva and tongue) and genital region may be found
Herpes simplex 1 and 2
HSV1/2 transmission
direct contact - sexual and birthing contacts
non-seasonal but associated w/ stress
HSV1/2 incubation
varies from 2d-2w, becomes latent and recurs
HSV1/2 communicability
not well defined, 1 to several weeks
dx of HSV1/2
clinical picture, recovery from lesion for cell culture, fluorescent antibody
HSV1/2 management
drying agents, acyclovir oint, oral/IV acyclovir/famciclovir/valacyclovir/penciclovir
protect newborns from exposure - pregnancy precautions
six mo old infact w/ high fever w/ minimal respiratory sxs preceeding. Infant seems playful in spite of fever. After about 3 days, fever breaks and fine maculopapular rash develops on neck and trunk then disappears in two days
HHV 6/7 roseola exanthem subitum (sixth disease)
HHV6/7 transmission
probably nasopharyngeal droplet
yearround
incubation HHV6/7
9 days
HHV6/7 communicability
early, during febrile stage
HHV6/7 dx
clinical course, non-toxic, but febrile infant (3mo to 3 yrs) w/ high fever, possible febrile convulsion, virus isolation possible
Fever clears when rash devleops
management sixth disease
antipyretics, ?ganciclovir, no isolation
observe for febrile convulsion
*frequently mislabel as penicillin allergy
Adolescent w/ sore throat, mild fever, enlarged lymph nodes, extreme tiredness over 3-4 days. Tiredness lingers a week or more as other sxs resolve. Maculopapular rash may be noted on trunk, possible jaundice.
Infectious mono “Kissing Disease”
Epstein-Barr Virus (herpesvirus 4)
EBV transmission
close contact
pharyngeal secretions
non-seasonal
EBV incubation
30-50 days
EBV communicability
indeterminate, but virus recovery for months after recovery
EBV dx
increased posterior cervical lymph nodes, tender and enlarged spleen, atypical lymphocytes, rapid mono test, heterophile Ab
EBV management
symptomatic tx, avoid contact sports, possible steroids, observe for jaundice, avoid tx w/ ampicillin
Young child w/ malaise, mild fever
sore throat, lesions in mouth and on extremities. Enanthem w/in 1-2 days after onset of sxs and exanthem shortly thereafter. Lesions clear within 1 week. Possibly ulcerative rash in posterior phalanx
Hand, Food and Mouth Disease
herpangina
coxsackievirus (enterovirus)
Coxsackievirus transmission
nasopharyngeal droplet, saliva, fecal
peaks in summer, early fall
incubation coxsackievirus
2-6 days
communicability coxsackievirus
possible for several weeks
coxsackievirus dx
clinical appearance, virus isolation from mucous membranes, feces, serology
management coxsackievirus
symptomatic medications, protect newborns, good handwashing, personal hygiene
Child w/ flu-like process w/ mild fever, malaise, abdominal cramping, diarrhea, and non-specific maculopapular rash on trunk. Rash fades over 5 days, after other sxs gone.
Non-specific viral exanthem Echo virus (enterovirus)
Echovirus transmission
fecal to oral route
peaks in summer and early fall
incubation echovirus
3-6 days
Echovirus communicability
several weeks during fecal viral shedding
echovirus dx
clinical course, viral isolation from feces, serology
echovirus mngmnt
symptomatic meds, personal hygiene, care w/ diaper changing
Non-specific respiratory virus w/ possible exanthem - causative agent
Enterovirus D-68
Enterovirus D-68 transmission
respiratory secretions, most serious in asthma, may be found in fecal excretions
peaked last year in mid-August
Incubation enterovirus D68
1-5days
communicability D68
1 day prior to 5 days after onset
Dx D68
clinical course, PCR serology
episodes of paralysis of arms and legs?
D68 management
symptomatic meds, personal hygiene, admission if asthma or serious respiratory sxs
Gradeschool child w/ very mild upper respiratory illness, then very red slapped-cheeks rash on face. OVer few days, fades and lacy rash noted on upper extremities. This may fade only to return in couple of weeks, maybe some vague joint complaints
Erythema infectiosum, fifth disease
Human parvovirus B19
Parvovirus B19 transmission
nasopharyngeal droplet, possible via blood
peaks in spring
B19 incubation
4-14 d
B19 communicability
from before onset of rash to shortly after rash appears
once rash - no need to keep out of school
B19 dx
clinical appearance, serology
B19 management
symptomatic meds, personal hyg. protect pregnant women from exposure.
Young unvaccinated from travel - week later, upper resp sxs w/ rhinitis and cough, conjuctivitis. Discrete red rash gradually becoming confluent as spreading from central to distal body sites. High fever. Koplik spots on buccal mucosa. Total illness lasts 1 week.
Rubeola (measles)
Paramyxovirus
Measles transmission
nasopharyngeal droplets, direct contact
peaks in winter, spring in 2-5 year cycles
measles incubation
8-12 days
measles communicability
1-2 days before onset of sxs (3-5 days before rash) to 4 days after onset of rash
dx measles
clinical appearance, serology for acute/convalescent sera, possible SSPe
management measles
isolation, symptomatic medications, vit A
active immunization, immunoglobulin if exposed IC
School age child w/ mild upper resp sxs and malaise, low grade fever. Shortly thereafter, fine maculopapular rash on upper body and spreads to lower body. Clears in same fashion over 3 days. Enanthem (forchheimer spots) may appear on soft palate/uvula. Some joint pain and cervical lymph nodes may be present.
Significant congential form may develop in fetuses exposed in early pregnancy.
Rubella = German measles
Togavirus
Rubella transmission
nasopharyngeal droplet, direct contact, maybe stool/urine
peaks winter/spring, occurs in 6-9 year cycle
rubella incubation
16-18 d
rubella communicability
7d before to 5 days after onset of rash
rubella dx
clinical course and appearance of rash, suboccipital and posterior auricular nodes, serology on acute and convalescent sera
rubella management
isolation, symptomatic meds
active immunization
consider globulin in susceptible/pregnant women
High grade fever suddlenly, lasting 1-5 days, hx of travel
some joint pains, sore throat, cough w/ significant general malaise and vomiting. After fever, non-descript generalized rash, sparing soles and palms. Individual appears ill and toxic. There is a fatal hemorrhagic form.
Dengue fever Dengue virus (arbovirus) and no chikungunya virus
Dengue fever transmission
mosquitoborne
not present about or below 25degrees N/S
Not seen in winter months
Dengue fever incubation
3-8 days
Dengue fever communicability
Over lifetime of infected mosquito- up to70 days
Dengue fever dx
biphasic fever, pharyngitis, arthralgias, generalized maculopapular rash, not on pals/soles, serology
dengue fever management
symptomatic meds
use of screened windows, insect repellant
Big differential dx of other conditions w/ rash
scarlet fever, pityriasis rosea, impetigo, meningococcemia
