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What is an exanthem?
SKIN rash/eruption or disease in which skin rashes/eruptions are prominent
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What is an enanthem?
An eruption on a MUCOSAL surface
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What is a macule?
Discoloured area on the skin NOT ELEVATED above the surface
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What is a papule?
SMALL, circumscribed, superficial, solid ELEVATION of skin
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What is a vesicle?
SMALL, circumscribed EPIDERMAL ELEVATION, less than 5mm usually containing clear fluid
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What is spread of measles?
Airborne and direct contact with respiratory secretions eg kiss
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Who is the attack rate of measles high in?
Unimmunised (people who haven’t had MMR)
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What is the mortality of measles in UK?
Low as developed
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What are the 3 C’s of measles?
- Coryza
- Cough
- Conjunctivitis
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What are clinical features of measles?
Prodromal features 3-5 days: cough, coryza, malaise, fever, conjunctivitis
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What is a characteristic feature in the prodrome of measles?
Koplik’s spots in bucclal mucosa inside cheek and mouth. White, opposite molar usually. Like grains of salt
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What appears 4-5 days after onset of symptoms?
Maculopapular rash: starts on face and spreads downwards
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How infectious is measles and what is timing of infectivity?
- Highly infectious – up to 90% of contacts are infected
- Infectious period: 4 days before and after rash onset
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What are the 2 main categories of complications of measles? And give eg of the actual complications. Concentrate on immunocomptent patient
- Respiratory: opportunistic secondary infections of epithelial surfaces (as this is destroyed by virus so strep and staph can get in) eg respiratory tract, pneumonia, otitis media, bronchitis
- CNS: acute measles post infectious encephalitis, decades after primary infection can get SSPE – subacute sclerosing panencephalitis
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How does SSPE present?
In puberty with decline in mental function and seizures
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What are 2 major comlpications of measles specifically in immunoCOMPROMISED?
- Resp: measles giant cell pneumonia (virus fuses cells and get syncytium)
- CNS: subacute measles encephalitis
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How is diagnosis of measles made?
- Detect measles specific ANTIBODIES: IgM or IgG seroconversion
- Detect measles NUCLEIC ACID in acute serum, oral fluid (saliva) or urine.
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What is treatment of measles?
- No specific treatment – warn if get signs of complications then come back
- Give antibiotics for secondary bacterial infections: otitis media or pneumonia
- Paracetamol to reduce fever
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How is measles prevented?
MMR vaccine. Live attenuated. Need 2 doses for a good response (1st at 13-15months, 2nd at 3-4 years)
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If there are susceptible contacts (pregnant, HCW, immunocomp) who are non immune, how is measles prevented?
Human normal Ig
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If you see a case of measles what do you have to do?
- Notifiable disease
- Report to CCDC
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What is the other name for rubella?
German measles
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How is rubella different from measles
- It is MILD
- But can cause severe fetal congenital abnormalities early in pregnancy (1st trimester)
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When do we worry about rubella?
Pregnancy
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How is rubella spread?
Droplet and direct contact with resp secretions
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What are 3 main symptoms of rubella
- 1. Mild fever
- 2. Macular rash – fine
- 3. Lymphadenopathy: suboccipital, post auricular, cervical nodes
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Name 3 major complications of rubella?
- 1. Joint involvement – esp adult women
- 2. Thrombocytopenic purpura – low platelets
- 3. Fetal damage (congenital rubella syndrome)
- What is the congenital rubella triad?
- Cardiac
- Ophthalmic
- Auditory
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How is rubella diagnosed?
- Detect rubella specific antibodies: IgM or IgG seroconversion (if post natal will only have IgM)
- Detect rubella nucleic acid ONLY for prenatal diagnosis of fetal infections
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What is treatment of rubella?
No specific management
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How is rubella prevented?
MMR vaccine
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Give 3 other names for human parvovirus B19 disease
- 1. Fifth disease
- 2. Erythema infectiosum
- 3. Slapped cheek disease
- How does parvo B19 spread?
- Contact with respiratory secretions
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Where do you get outbreaks of parvo B19?
Primary schools
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How many phases are there to parvo B19 infection? Describe them
- Biphasic
- First phase: non-specific symptoms for 2-3 days: fever, myalgia, chills, malaise, or subclinical
- 7 days symptom free
- Then exanthematous phase: red rash on cheeks (slapped cheek), circumORAL pallor
- Then the erythematous maculopapular rash spreads to trunk and limbs
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What happens to the rash as it clears?
- Central clearing of the rash follows
- Giving a lacy reticular appearance
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Which complication of B19 happens to women?
Joint involvement
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What is complication in pregnancy?
- Fetal loss
- Hydrops fetalis: heart failure due to anaemia
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What is complication of B19 in patients with chronic haemolytic anaemia?
Aplastic crisis
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What happens if immunocompromised get B19?
- Persistent anaemia
- Need iv Ig
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What 2 ways can you diagnose parvo B19?
- Detect B19 nucleic acid in fetus or immunocompromised
- Detect B19-specific antibodies: IgM or IgG seroconversion
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What is the treatment of B19?
- No antiviral drug
- ivIg for persistent anaemia
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how many kids get HHV6/7?
- Most children get it
- Hhv6 up to 2 years
- Hhv7 up to 5 years
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What is mode of spread of hhv6/7?
Saliva
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What does primary infection of HHV6 give?
- Exanthem subitum aka roseola infantum
- Fever for 3-5 days (often with fits) – common cause of status epilepticus in children 1-2 years old
- Followed by rose pink macular rash
- What is HHV6 rash easily confused with?
- Measles or rubella rash
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Which childhood virus causes febrile fits?
HHV6
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How is HHV6/7 diagnosed?
- Detect specific Ab IgM/IgG seroconversion
- HHV6/7: nucleic acid in acute serum
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What is treatment of HHV6
No antiviral drug
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What type of rash do you get with herpes SIMPLEX virus?
- Widespread
- Vesicular rash
- Due to disseminated herpes simplex virus infections
- In perinatal, immunocompromsed, eczema herpeticum
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Which 2 viruses can cause a vesicular rash?
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What age and class to people get EBV?
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Where does EBV infect and replicate?
Oropharynx
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Which cells are the primary cell type infected by EBV? And what happens to them?
B cells they stimulate vigorous T cell response which controls PROLIFERATION of infected B cells
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What happens to some of the B cells infected with EBV
They are latently infected with EBV for life
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How does IM begin – symptoms?
- Abruptly, sore throat (cant swallow), swelling of neck
- Fever
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What are the 2 types of rashes you get in IM?
- 1. Faint morbilliform rash
- 2. Maculopapular rash in any patient receiving amoxicillin/ampicillin
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What else can happen in the abdomen in IM?
- Splenic enlargement
- Mild hepatomegaly or jaundice
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Name 5 complications of IM
- 1. Thrombocytopenia
- 2. Splenic rupture
- 3. Guillain-barre syndrome
- 4. Meningitis
- 5. Encephalitis
- What are 4 differnetials of EBV IM?
- 1. CMV mononucleosis
- 2. Toxoplasmosis
- 3. Lymphoma/leukaemia
- 4. HIV seroconversion
- How is a lab diagnosis of IM EBV made?
- 1. Lymphocytosis with high WBC (15-20) >50% are T cells, many are large or atypical
- 2. Heterophile Ab are reactive to Ags present on sheep and horse RBCs and can be used to diagnose a primary EBV infection = the Paul Bunnell or Monospot test
- 3. EBV antibody tests
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What is the monospot test?
- Heterophile means it reacts with proteins across species lines
- The antibodies in the patients serum will agglutinate with horse RBC and then the test is +ve
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Which rashes can enteroviruses case?
- Hand foot and mouth disease: ulcers on buccal mucosa and painful vesicular lesions on hand and feet
- Rubelliform rashes: fine maculopapular rash is a feature of some enterovirus infections
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Which rashes can you get with HIV?
- 1. Seroconverting illness: get widespread PAPULAR, erythrmatous rash
- 2. Seborrheic dermatitis: erythematous scaling rash, typically affecting the face
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What is the rash in mumps like?
- There is no rash in mumps
- In this section as it is a childhood infection
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How is mumps spread?
Direct contact with saliva – respiratory route
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What are the 2 main clinical featuers of a patient with mumps?
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What happens after 2 days of mumps?
Facial swelling due to parotid swelling that is painful
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Why is there a recent increase in mumps?
Only received one dose of vaccine in childhood
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Name 4 complications of mumps
- 1. Meningitis
- 2. Orchitis
- 3. Pancreatitis
- 4. Oophoritis
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If you see a case of mumps, what do you have to do?
- Notifiable disease
- Need to report to CCDC (consultant of communicable disease control)
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How is mumps diagnosed?
- Clinically as parotid swelling is characteristic
- Antibody: detect mumps-specific IgM
- Detect virus in oral fluid – saliva or urine by VIRAL CULTURE or PCR for mumps nucleic acid
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How is mumps prevented?
MMR vaccine
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