Viral rash in pregnancy Flashcards
(36 cards)
Which viruses are implicated in cause of maculopapular rash in pregnancy?
Exanthema is widespread skin rash accompanying a disease or fever
enterovirus - Coxsackie A + B, Echovirus, Enterovirus 68-71
human herpes virus 6
human herpes virus 7
measles
parvovirus B19
rubella
varicella - discussed in separate section
EBV human herpes virus 4 and CMV human herpes 5, both are unlikely to present primarily as rash, but should be considered in differential
Measles and rubella are notifiable diseases
What are other bacterial/ viral rarer causes of rash in pregnancy?
Streptococcal
meningococcal disease
syphilis
Dengue virus
Zika
Parvovirus is smallest DNA virus (parvo=small), B19 only strain to infect humans
Infection commonly occurs between ages 3-15, with over 50% infected by this point. One attack provides lifelong immunity.
What is transmission route?
Vertical via placenta
Respiratory droplets
Blood transfusion
Bone marrow transplant
Infectivity rates lower than most viruses
Parvovirus B19, what is incubation period, and when are they infective
50% population been infected with parvovirus at some point
7-14 days incubation
7-10 days before rash appears
Infective from 10 days before rash appears, until 1 day after rash
If pregnant woman has exposure on day 0, she must avoid pregnant woman/ immunocompromised either -
- until 11 days until disease develops and non-infectious
- until proven to be immune
What are symptoms of parvovirus B19 infection?
General - sore throat malaise fatigue abdominal pain arthralgia
Then become symptoms free for a week, before “slapped cheek” erythema rash develops, which lasts couple of days
About 1-4 days after the facial rash appears, an erythematous macular/morbilliform rash develops on the extremities, mainly on the extensor surfaces. Can be itchy in adults
Aplastic crisis - virus has affinity for RBC precursors, so can cause significant problem if have udnerlying disease eg, sickle cell anaemia, thalassaemia, hereditary spherocytosis and iron-deficiency anaemia.
Meningoencephalitis
Parvovirus B19 also called fifth disease, as fifth on childhood list of rash causing diseases.
What are the other diseases?
Measles Scarlet fever Rubella Duke's disease - no longer in use Parvovirus B19 Roseola - HHV 6/7
Pregnant women who develop erythema infectiosum (parvovirus B19 infection) have a 30% chance of passing it on to their unborn baby
Maternal symptoms often short-lived.
During the first trimester the risk of fetal complications is heightened.
What are complications for unborn baby?
foetal loss - 10% risk hydrops fetalis - accumulation oedema in foetal compartments hepatitis severe anaemia, myocarditis/ heart failure
Maternal asymptomatic parvovirus B19 infection is as likely to infect and damage the fetus as symptomatic infection.
All pregnant women who have a non-vesicular rash, or contact with someone who has a non-vesicular rash, should be investigated for parvovirus and rubella infection - irrespective of past history, previous serology or gestation:
Contact is defined as being in the same room for >15 minutes or face-to-face contact; however, for parvovirus, this is probably over-cautious, the main risk of infection being from household contacts or prolonged occupational contact.
What tests are required for parvovirus infection?
Parvovirus IgG/ IgM - on booking blood
or
Parvovirus IgM on latest bloods. Needs to be within 4 weeks of exposure, but also not taken to early. If taken early, consider parvovirus DNA titre
Booking blood are usually kept for 2 years to assist with investigations in neonate.
Pregnant patient tests positive for parvovirus, what is management?
Refer fetal medicine -
- fetal blood sampling - PCR to confirm infection
- intrauterine transfusion
- serial USS
- early delivery
At pregnancy booking visit with midwife, what history should be documented regarding infectious diseases?
MMR vaccination history
Varicella vaccination history
Enquire if had rash in pregnancy, and advise if they get a rash to seek medical review
Pregnant patient presenting with rash, what a key parts of history?
Date of onset
Clinical features -
- distribution
- vesicular or not
- how it has evolved
Contact with people with rash
Pregnancy details - gestation
Vaccination history - beware foreign patients may have incomplete vaccination history
Recent travel
What are symptoms of measles infection in children/ adults?
Measles is RNA virus
General - fever, malaise
Conjunctivitis
Coryza
Encephalitis
Otitis media
Koplik’s spots - reddish spots on buccal mucosa, with white dot. Prodrome, and fade when morbilliform rash develops
Rash - morbilliform (measles-like). Initially forehead/ neck. Then trunk/ limbs
Pneumonia
What is incubation period of measles?
When are patients with measles potentially infective?
7-21 days
4 days before rash appears, until 4 days after appears
Measles infection
What are risks to mother/ baby in pregnancy?
What are risks to children/ adults?
Baby -
- foetal loss
- prematurity/ LBW
- subacute sclerosing panencephalitis SSPE
Children/ adults -
- pneumonia
- subacute sclerosing panencephalitis SSPE
- acute demyelinating encephalitis
- measles inclusion body encephalitis
Those with vitamin A deficiency are at higher risk of significant disease.
In developing countries, measles is biggest cause of vaccine preventable death.
How is measles transmitted?
Airborne via respiratory droplets
One of most highly infectious pathogens
Investigations for suspected measles
Oral fluid swab - IgM/ RNA
Serum for measles IgM/ IgG
Needs to be taken within 6 weeks illness
What is management of confirmed measles for mother/ baby?
Ideally should have received HNIG at time of exposure
Mother - no specific treatment. Monitor for signs pneumonitis. Ribavirin can be used in severe cases
Neonate - Human normal immunoglobulin (HNIG) is recommended for neonates born to mothers
who develop a measles rash 6 days before to 6 days after delivery.
If just suspected exposure to measles (not yet confirmed), what are guidelines for post-exposure prohpylaxis? (first test for susceptibility)
Pregnant
Infant
Immunocompromised
Healthy adult
- 2x doses of MMR is considered immune, and does not require HNIG
- Pregnancy - very high proportion of pregnant women will be immune. Cannot have MMR in pregnancy. If had exposure, check immune status, and if susceptible - give human normal immunoglobulin
- <6 months - give HNIG
- > 9 months - give MMR within 72 hours
- immunocompromised - HNIG if severe deficiency. If minor deficiency e.g steroid use, will likely be immune
- Healthy adult - MMR vaccination within 72 hours of exposure. If incubating measles, mumps or rubella, the MMR vaccination will not exacerbate the symptoms.
HNIG given with 72 hours (up to 6 days)
HNIG can be given IM
Can await measles IgG result firstly
See detailed PEP guidelines PHE
Rubella rare in UK. Cases occur in spring/ early summer. Also known as German measles
RNA virus
How is it transmitted?
What is incubation period?
airborne droplets between close contacts (unlike most togaviruses which are arthropod-borne)
incubation period is 14-21 days
infectious for up to seven days before and four days after symptoms appear.
Rubella symptoms for mother
Usually self-limiting. 20-50% cases asymptomatic
General - fever, conjunctivitis, coryzal symptoms
Lymphadenopathy
Arthralgia
Macular rash
Rubella symptoms for baby
- Infection in weeks 8-10 of pregnancy results in damage in up to 90% of surviving infants. Multiple defects are then common.
- risk of damage reduces to 10-20% if the infection is in weeks 11-16 of pregnancy.
- Fetal damage is rare over 16 weeks of gestation.
Transient:
Intrauterine growth restriction
Thrombocytopenic purpura (25% - ‘blueberry skin’)
Haemolytic anaemia
Hepatosplenomegaly
Jaundice (common)
Radiolucent bone disease (20%)
Meningoencephalitis (25%) +/- neurological sequelae.
Developmental:
Sensorineural deafness (80%) - rubella is the most common cause of congenital deafness in the developed world.
General learning disability (55%).
Congenital heart disease
Eye defects including cataracts, congenital glaucoma, pigmentary retinopathy
Microcephaly
What are tests for rubella infection?
serology - IgM/ IgG
IgM dose not cross placenta. So check neonate for IgM, and PCR of blood
What is management of rubella infection in pregnancy?
No specific treatment available
If within first 16 weeks - offer termination
cochlear implants
cardiac surgery
No evidence of immunoglobulin being effective
HHV-6 and HHV-7 are universal infections.
What problems can they cause in pregnancy?
Can cause rash - roseola. Most people have as children
Not implicated in any serious conditions with congenital infection
