Infectious diseases with maculopapular rash – measles, german measles, fifth disease and sixth disease. Flashcards
what is the epidemiology of measles ?
it is highly contagious
4 days before and 4 days after the onset of xanthem
peak incidence of less than 12 months
short contact over a distance of few meters
what is the aetiology of measles ?
measles virus
what are the characteristics of measles virus ?
morbilli genus
paramyxovirus family
what is the incubation period of measles virus ?
2 weeks
what are the clinical manifestations of measles virus ?
prodromal phase
lasts 4-7 days
- fever ,
cold ,
barking cough ,
conjunctivitis , photosensitivity
KOLPIK SPOTS (enanthem) - white or bluish grey spots on irregular erythematous background in the buccal mucosa
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exanthema phase
develops 1-2 days after enanthem
lasts for 7 days
generalised lymphadenopathy
second fever PEAK - fever
usually on face and trunk
erythematous maculopapular , blanking partially confluent exanthema
- begins behind the ear
disseminates to the rest of the body towards the feet - palm and sole involvement is rare
fades after 5 days - leaving brown discolouration and disqualification
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recovery
cough persists for another week
what are the diagnostics of measles ?
lab
DECREASE in leukocytes and platelets
serology
GOLDEN STANDARD - measles specific IgM
IgG antibodies
RT PCR
biopsy - lymph nodes - warthin-finkeldey cells - multinucleated giant cells
what is the treatment of measles ?
no antiviral therapy is there - only supportive therapy
antipyretics, antitussives, fluid substitution
SELF isolate
vit a - reduces morbidity and mortality (especially in malnourished children)
PEP- in patients
what is the complication of measles ?
subacute sclerosing panencephalitis
- generalised lethal demyelinating inflammation of the brain caused by persistent measles virus infection
primarily affects male between 8-11 years of age
stage 1 - dementia
stage 2 - epilepsy
stage 3 - decerebration
stage 4 - veg state
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bacterial superinfection
otitis media
pneumonia
gastroenteritis
acute encephalitis
Giant cell pneumonia
what is the prognosis of measles ?
good in uncomplicated cases
Fatal in newborns and immunocompromised patients
what are the prevention of measles ?
Live vaccination with attenuated virus in combination with mumps and rubella (MMR) vaccine and possibly varicella (MMRV) vaccine
Infants: two vaccinations during childhood
First dose between 12 and 15 months; second dose between 4 and 6 years or at least 28 days after the first dose.
idividuals >18y
without vaccination or with unknown
immunization status
1 dose with MMR(V) -
vaccine
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Postexposure prophylaxis (PEP) Indication: negative or indeterminate serology
Methods
Active immunization for immunocompetent individuals after direct exposure
Passive immunization for chronically ill and immunocompromised individuals
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immunoglobulins: administration max. until 6d after exposition
ind: immunodeficient patients, unvaccinated patients (infants <6m, pregnant
women)
after immunoglobulin therapy a vaccination is not safe for 8m
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Measles is a notifiable disease.
Cases should be reported within 24 hours
what are the differential diagnosis of measles ?
6 paediatric exanthema diseases:
1.
measles
2.
Scarlet fever
3.
rubella
4.
Morbus Dukes- Filatow
5.
Erythema
infectiosum
6.
Exanthema subitem
what is german measles ?
rubella
what are the characteristics of rubella ?
member of the Togaviridae family and
only member of the genus Rubivirus
single-strand RNA enveloped virus
humans are its only known reservoir
what is the pathogenesis of rubella ?
they are MOST contagious while the rash is erupting
but virus can be shed from the throat 10 days before and 15 days after the onset of the rash
infants and those with congenital rubella can shed the virus for many months
someone with the vaccine do not spread rubella
rubella replicates in the nasopharynx and migrates into the lymph nodes - causing viremia
just like with measles the rubella rash appears as immunity develops and virus has dissapered from the blood
what is the incubation period of rubella ?
7-28 days
how is rubella transmitted ?
respiratory droplets
what are the clinical manifestation of rubella ?
prodromal phase
lasting 1-5 days
post auricular and sub occipital , lymphadenopathy
ocasional splenomegaly
non specific symptoms - low grade fever , conujunctivitis , sore throat ,
arthralgia and arthritis are common in infected adults
forchiemer signs - enenthamen of the soft palate - but this enanthem is not
diagnostic for rubella (unlike Koplik’s spots in
measles)
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exanthema phase
lasts 2-3 days
In children, rash is usually the first sign of illness,
which lasts 3-5 days and disappears, that is why
it also called „3 -day Measles!!!!!
in older children and adults: prodrome often
precedes the rash
fine non confluent pink maculopapular rash
begins at HEAD , behind ears then to trunk extremities sparing plasma and soles
rash is pruritic in adults
polyarthritis
riad of fever, rash and swollen tender lymph nodes =Theodor’s sign
what is the prognosis of rubella ?
age is the major determinant how severe rubella is !
acquired ( post natal) - subclinical
what is the fatal complication of rubella ?
congenital rubella syndrome
Infection in first 2 months of pregnancy: 90% defect, 2-3 months:
some defects, 3-4 months: only 10% defect
Infant will be carrier after second year of age and becomes the main
reservoir
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Chronic arthritis (especially women)
Thrombocytopenic purpura
Rubella during pregnancy
(TORCH infection): congenital rubella syndrome
Rare: rubella encephalitis,
what is the clinical manifestation of german measles ?
physical defects, which most commonly relate to the
eyes, ears, and heart
=
triad of Gregg
(CCD = cardiac defect - paint ductus arteritis and pulmonary artery stenosis ,
conjunctivitis and cataracts - salt and pepper retinopathy , glaucoma
bilateral sensorineural hearing loss - cochlear defect )
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early - hepatosplenomegaly
jaundice
haemolytic anemia
thrombocytpenia - blueberry muffin
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late
cns defects - microcephaly , pan encephalitis
skeletal abnormalities
diagnosis of rubella ?
Laboratory tests
CBC: leukocytopenia, increased plasma cells
CBC: leukocytopenia with relative lymphocytosis and increased plasma cells
Confirmatory test: serology
Detection of IgM antibodies
≥ 4-fold increase in IgG titer
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prenatal diagnosis
newborn and mother
PCR for rubella RNA (throat swab, CSF)
Serology (abnormally high or persistent concentrations of IgM and/or IgG antibodies)
Viral culture (nasopharynx, blood)
Fetus
IgM antibody serology (chorionic villi, amniotic fluid)
PCR for rubella RNA
placental biopsy at 12 weeks is possible
what is the treatment for rubella ?
Symptomatic treatment
Severe pruritis: antihistamines
Severe polyarthritis: rest and nonsteroidal anti-inflammatory drugs
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during pregnancy: serological tests must be made in first trimester ->
elevated IgG?-> second probe after 2 weeks!
-
-> still elevated? => abortion
dd of diagnosis ?
scarlet fever, mild measles, infectious
mononucleosis, toxoplasmosis, roseola, erythema infectiosum
prevention of rubella ?
vaccination -> lifelong immunity
Live attenuated virus
first dose of MMR vaccine at 12–15months of age
and a second dose at 4–6 years
pregnant women should not get vaccinated, due to transmission
of vaccine to fetus
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Check vaccination status
ELISA (preferred method), latex agglutination, hemagglutination inhibition, or immunofluorescent antibody assay.
what is fifth disease ? and what is the etiology?
Erythema infectiosum
what is the epidemiology od erythema infectiousum?
Peak incidence: 5–15 years
Humans are the only reservoir for parvovirus B19
Only contagious before onset of rash!!!
what is the route of transmission of erythema infectiousum?
aerosol
Other routes
Hematogenous transmission
Transplacental transmission: In seronegative pregnant women, transmission to the unborn fetus may occur
incubation period of fifth disease ?
4-14 day
what are the clinical manifestations of fifth disease ?
commences with high fever and malaise, when the virus
is most abundant in the bloodstream, and patients are usually no longer infectious
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Exanthem: 2–5 days following the onset of cold‑like symptoms - adults less likely to present with it
bright red rash of the cheeks with relative pallor around the
mouth gives it the nickname
“slapped cheek syndrome”.
Spread of exanthem to the extremities and trunk
Initially confluent and maculopapular; adopts a lace‑like, reticular appearance over time as it clears.
Associated with mild pruritus (in ∼ 50% of cases)
it is on trunk or extremities
Infection in adults usually only involves the reticular rash, with multiple joint pain
predominating.
Fades after ∼ 7–10 days; can be recurrent over several weeks (becoming more pronounced after exposure to sunlight or heat)
what is the diagnosis of erythema infectiousum?
based on clinical presentation alone
what is the diagnosis of erythema infectiousum?
IgM Appears within ∼ 10 days of initial exposure
IgG - approx. 2 weeks following infection
Enzyme-linked immunosorbent assay (ELISA), radioimmunoas
say (RIA)
-
Dot blot hybridization
-
Polymerase chain reaction (PCR) assay
what is the treatment of fish disease ?
Antipyretics (i.e., fever reducers) are commonly used.
Short course of low‑dose prednisone for parvovirus B19‑associated arthritis
what is the prevention of fish disease ?
Njama Vaccination
what is sixth disease
and what is their etiology ?
Exanthema subitum
also called Roseola
caused by two human herpesviruses:
human herpesvirus 6 (HHV-6) and human herpesvirus 7 (HHV- 7), which are sometimes referred to collectively as Roseolovirus –> MAINLY HHV-6!!!!!
what is the epidemiology of Exanthema subitum?
Most infections occur before the age of three.
what is the incubation of roseola?
5–15 days
how is the sixth disease transmitted ?
Transmission occurs via
saliva
what are the clinical manifestations of roseola?
vary from absent to the classic presentation of a fever of rapid onset fever generally l asts for three to five days
followed by a rash.
generally pink and las
ts for less than three days.
fever generally lasts for three to five days
what are the clinical manifestations of roseola?
vary from absent to the
classic presentation of a fever
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Febrile phase
Duration: 3–5 days
of rapid onset high fever >40c
generally lasts for three to five days
rare cases, this can cause febrile convulsions
Cervical, postauricular, and/or occipital lymphadenopathy
Nagayama spots: papular enanthem on the uvula and soft palate
Inflamed tympanic membranes
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Exanthem phase
Duration: 1–3 days
Characteristic presentation: subsequent sudden decrease in temperature and development of a patchy, maculopapular exanthem generally pink blanches upon pressure usually begins on the trunk ( torso) and then spreads to the arms, legs, and neck lasts for less than three days.
{In contrast, a child suffering from measles would usually appear sicker, with
symptoms of conjunctivitis, cold-like symptoms, and a cough, and their rash
wouldaffect the face and last for several days. }
fever generally lasts for three to five days
what are the complication of Exanthema subitum?
febrile seizures - febrile seizures arenot harmful, do not require treatment, and have no long term negative effect
meningitis
Like other herpes viruses, HHV-
6 then remains latent
HV-6 is a major cause of morbidity and mortality in patients who are immunosuppressed, particularly in patients with AIDS and in those who are
transplant recipients
how to diagnose Exanthema subitum?
clinical diagnosis
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Laboratory tests
Antibody testing: HHV-6 IgM detection is possible.
immunoblot analysis
Viral DNA testing: via PCR (possible detection using blood, urine, cerebrospinal fluid, or saliva samples
what is the treatment for sixth disease ?
fluids and possibly acetaminophen to reduce fever)
If encephalitis occurs
ganciclovir or foscarnet may be useful
