Exanthems Flashcards
exanthems
generalized skin eruption secondary to systemic infxn
most common cause of EX
viral, but can be caused by bacteria (GAS, S. aureus, meningococcus)
the exanthem (or rash) is precede?
yes, by a prodrome, think fever, malaise, sore throat, Nv, abdominal pain
enanthems
oral lesion
most common viral exanthems
rubeola (measles), rubella (german measles), varicella, roseola (6th dz), Erythema infectiosum (fifth dz)
scarlatiniform
generalized erythema, worse in body creases
morbilliform
maculopapular
vesicular
intially vesicles, may evolve to papules then pustules, then erosions
rubeola
aka first dz, measels
SS RNA paramyxovirus
4 pahses of rubeola
incubation (8-12 days), prodromal (catarrhal), exanthematous (rash), recovery
prodromal phase
cough, coryza, conjunctivitis, Koplik’s spots (gray-white oral lesions on the buccal mucosa opposite the lower molar
rash
Conjunctiva may reveal a Stimson line (transverse line of inflammation along eyelid margin) may last 12-14 hours
o Maculopapular rash in hairline & spreads to trunk, extremities (cephalad to caudal pattern). May also note cervical lymphadenitis, splenomegaly, and mesenteric LAD with abdominal pain. Otitis media, pneumonia, and diarrhea are common in infants
tx for rubeola
- Self-limiting 7-10 days
- Rx symptomatic (hydration and antipyretics). Vitamin A supplements if at high risk for complications
most common complication of rubeola?
otitis media
- SSPE (Subacute Sclerosing Panencephalitis)
rare fatal encephalitis years after initial infection – behavioral and intellectual deterioration with eventual death
prevention for rubeola?
MMR vaccine at 12-15 months and 4-6 years
rubella
- German Measles, 3 day measles. Third disease. Caused by a single-stranded RNA. Humans are the only natural host.
- Virus invades the respiratory epithelium and disseminated via a primary viremia
- Usually occurs in spring (but rare due to vaccination). Incubation period 14-23 days
signs of rubella
retroauricular, posterior cervical, and posterior occipital LAD accompanied by an erythematous, maculopapular, discrete rash that starts on the face and then spreads – it resolves in 3 days (rash is less prominent than with measles)
o Rose-colored spots on the soft palate are called Forchheimer spots may develop before the rash
o Other manifestations – mild pharyngitis, conjunctivitis, anorexia, headache, malaise, low-grade fever (on the first day of rash only)
- Congenital rubella syndrome
significant morbidity from infection in utero. Maternal infection during the first trimester results in fetal infection and generalized vasculitis
common complciations
arthralgias
roseola
- Exanthem subitum. Sixth disease. HHV6, HHV7
- Peaks between 6 months and 2 years old
roseola CF
- 3-7 days of high fever > 39.0°C (103.0°F). Rash occurs after the fever has resolved
- Defervescence precedes rash (initially appears on trunk
Varicella
- Primary infection with VZV. Incubation 10-20 days
- Starts on trunk, then face, head, extremities less so. Also mucous membranes
- Lesions appear in crops over 3-4 days; up to 500. Crust in 3-5 days
varicella prodrome
- Prodrome of fever, malaise, anorexia, and occasionally a scarlatiniform or morbilliform rash
o Characteristic pruritic rash begins the next day – starts on trunk and spreads peripherally
o Rash starts as red papules that rapidly develop into clear vesicles 1-2 mm (dew-drop on rose petal). Vesicles then become cloudy, rupture, and then crust - Intensely pruritic, fever can reach 105°F
- Contagious from 24 hours before rash until all lesions have crusted (usually 1 week)
complications of varicella
pneumonia, encephalitis; can be fatal
varicella dx
Tzanck smear for multinucleated giant cells
varicella tx
symptomatic, no ASA (increased risk of streptococcal cellulitis, also risk of Reye’s syndrome)
o Can give oral antihistamines for pruritus Tz
o Consider acyclovir in teens
o If immunocompromised and exposed, give IVIG within 96 hours of exposure
o Administration of varicella vaccine within 72 hours of exposure can prevent or lessen severity
Zoster
reactivation of VZV
o Varicella dormant in dorsal root ganglia
prodrome of VZV
pain, tingling, dermatome distribution, fever, malaise
o Usually clears in 7-14 days, but can last a while with persistent pain (postherpetic neuralgia)
o Lesions are typical of herpes – grouped vesicles on an erythematous base
tx for zoster
symptomatic; pain meds in older, acyclovir in compromised children
Erythema infectiosum
- Fifth disease. Caused by human parvovirus B19 (affinity for infecting RBCs)
o In a child with hemoglobinopathy, a transient aplastic crisis precedes the onset of “slapped cheeks” - Epidemics in spring
ER CF
- Mild flu-like illness
- Rash at 10-17 days (not contagious with rash) – starts as facial erythema and spreads to extremities in a reticular pattern
- Low-grade or no fever.
Erytema Infectiosum rashes
o Slapped cheeks (and circumoral pallor) first rash
o Maculopapular second rash
o Lacy arms & legs third rash
complications
arthritis, mroe common in older women
mumps
2-3 wk intubation, paramyoxovirus
mumps CF
- Parotitis; bilateral in 70%
- The mandibular angle is obliterated
- Stenson’s duct may be erythematous with yellow discharge
mumps complications
orchitis, pancreatitis, oophoritis, aseptic meningitis
dx mumps
clinical (no rash); paired sera
H-F-M dz
- Coxsackie A-16. Usually in summer
- Highly contagious
HFM dz CF
- Vesicles on tongue, oral mucosa, hands & feet
- May also have generalized scarlatiniform rash
HFM prodrome
of low grade fever, anorexia, oral pain. Followed by crops of ulcers on the tongue and oral mucosa and a vesicular rash on the hands and feet (occasionally buttock and thighs)
o Individual vesicles have a “football” shape with surrounding erythema
complications of HFM
myocarditis, substernal chest pain, dyspnes
herpangina
if HFM limited to mouth
