What is an exanthem?
SKIN rash/eruption or disease in which skin rashes/eruptions are prominent
What is an enanthem?
An eruption on a MUCOSAL surface
What is a macule?
Discoloured area on the skin NOT ELEVATED above the surface
What is a papule?
SMALL, circumscribed, superficial, solid ELEVATION of skin
What is a vesicle?
SMALL, circumscribed EPIDERMAL ELEVATION, less than 5mm usually containing clear fluid
What is spread of measles?
Airborne and direct contact with respiratory secretions eg kiss
Who is the attack rate of measles high in?
Unimmunised (people who haven’t had MMR)
What is the mortality of measles in UK?
Low as developed
What are the 3 C’s of measles?
What are clinical features of measles?
Prodromal features 3-5 days: cough, coryza, malaise, fever, conjunctivitis
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
What appears 4-5 days after onset of symptoms?
Maculopapular rash: starts on face and spreads downwards
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
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
How does SSPE present?
In puberty with decline in mental function and seizures
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
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.
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
How is measles prevented?
MMR vaccine. Live attenuated. Need 2 doses for a good response (1st at 13-15months, 2nd at 3-4 years)
If there are susceptible contacts (pregnant, HCW, immunocomp) who are non immune, how is measles prevented?
Human normal Ig
If you see a case of measles what do you have to do?
- Notifiable disease
- Report to CCDC
What is the other name for rubella?
How is rubella different from measles
- It is MILD
- But can cause severe fetal congenital abnormalities early in pregnancy (1st trimester)
When do we worry about rubella?
How is rubella spread?
Droplet and direct contact with resp secretions
What are 3 main symptoms of rubella
- 1. Mild fever
- 2. Macular rash – fine
- 3. Lymphadenopathy: suboccipital, post auricular, cervical nodes
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?
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
What is treatment of rubella?
No specific management
How is rubella prevented?
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
Where do you get outbreaks of parvo B19?
How many phases are there to parvo B19 infection? Describe them
- 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
What happens to the rash as it clears?
- Central clearing of the rash follows
- Giving a lacy reticular appearance
Which complication of B19 happens to women?
What is complication in pregnancy?
- Fetal loss
- Hydrops fetalis: heart failure due to anaemia
What is complication of B19 in patients with chronic haemolytic anaemia?
What happens if immunocompromised get B19?
- Persistent anaemia
- Need iv Ig
What 2 ways can you diagnose parvo B19?
- Detect B19 nucleic acid in fetus or immunocompromised
- Detect B19-specific antibodies: IgM or IgG seroconversion
What is the treatment of B19?
- No antiviral drug
- ivIg for persistent anaemia
how many kids get HHV6/7?
- Most children get it
- Hhv6 up to 2 years
- Hhv7 up to 5 years
What is mode of spread of hhv6/7?
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
Which childhood virus causes febrile fits?
How is HHV6/7 diagnosed?
- Detect specific Ab IgM/IgG seroconversion
- HHV6/7: nucleic acid in acute serum
What is treatment of HHV6
No antiviral drug
What type of rash do you get with herpes SIMPLEX virus?
- Vesicular rash
- Due to disseminated herpes simplex virus infections
- In perinatal, immunocompromsed, eczema herpeticum
Which 2 viruses can cause a vesicular rash?
What age and class to people get EBV?
Where does EBV infect and replicate?
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
What happens to some of the B cells infected with EBV
They are latently infected with EBV for life
How does IM begin – symptoms?
- Abruptly, sore throat (cant swallow), swelling of neck
What are the 2 types of rashes you get in IM?
- 1. Faint morbilliform rash
- 2. Maculopapular rash in any patient receiving amoxicillin/ampicillin
What else can happen in the abdomen in IM?
- Splenic enlargement
- Mild hepatomegaly or jaundice
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
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
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
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
What is the rash in mumps like?
- There is no rash in mumps
- In this section as it is a childhood infection
How is mumps spread?
Direct contact with saliva – respiratory route
What are the 2 main clinical featuers of a patient with mumps?
What happens after 2 days of mumps?
Facial swelling due to parotid swelling that is painful
Why is there a recent increase in mumps?
Only received one dose of vaccine in childhood
Name 4 complications of mumps
- 1. Meningitis
- 2. Orchitis
- 3. Pancreatitis
- 4. Oophoritis
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)
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
How is mumps prevented?