A brief description of viral infection: Rubella affecting children and pregnant ladies. Also called German Measles. Helpful for medical students, doctors, and nurses, dermatologists, pediatricians. Fetal rubella syndrome

1. Viral Exanthem Part III:
Rubella:

2. Introduction:
Well recognized Exanthem caused by the Rubella virus of the genus
Rubiviris and Family of Togaviridae.

3. Epidemiology:
Incidence and prevalence
 Epidemics occur during the spring.
 Transmission via droplets from the nasopharynx.
 Infectivity is greatest at the end of the incubation period and falls
rapidly during the 4 days after the appearance of the rash.
Age
 Infection is most common amongst older children and young adults.

4. Pathophysiology:
Causative organisms
 Rubella virus is a member of the Rubivirus genus of the family
Togaviridae.
 Four types (1E, 1G, 1J and 2B) account for over 70% of infections.

5. Clinical features:
 Incubation period of about 14 days (range 12–21 days).
 Children rarely experience prodromal symptoms
 Adults have a brief prodromal illness lasting 1–5 days:
 Fever up to 39°C,
 Headache and malaise,
 sore throat without coryza and
 suffusion of the conjunctivae with a gritty sensation.
 The symptoms subside as the rash develops.
 Forschheimer sign: An enanthem of dull‐red macules or petechiae confined to the soft
palate is present in up to 20% of patients during the prodromal period or on the first day of
the rash.

6. Lymphadenopathy:
 Begins 5–7 days before the rash appears and reaches a maximum on the first or second
day of the rash.
 Lymphadenopathy is generalized but characteristically involves the suboccipital,
postauricular and cervical glands.
 The tenderness of the glands subsides after a day or two but palpable enlargement may
continue for several weeks.

7. Rash:
 Appears towards the end of the Incubation period.
 Appears first on the face and spreads rapidly downwards to the trunk and limbs.
 Consists of pink macules, at first discrete, but soon becoming confluent leading to a diffuse
erythema.
 On the second day, the face begins to clear and the macules on the trunk show some
coalescence, those on the limbs remaining discrete.

8. Complications and co‐morbidities
 In older children and adults:
 Arthritis affects up to 70% of females and 5% of males.
 Arthritis usually resolves within a month.
 Purpura – thrombocytopaenic or non‐thrombocytopaenic
 Encephalitis
 Haemophagocytic syndrome

9. Rubella in pregnancy:
First 11 weeks:
 The overall risk of fetal damage and multiple birth defects: 85%.
 Most of the defects are of neurological nature.
 Heart and eye damage is most frequent in embryos infected under 6 weeks;
Between weeks 12 and 16:
 The risk defect: 35% and is principally that of deafness.
 Mental deficiency occurs in embryos of all ages up to about 16 weeks.
After 16 weeks:
 Although fetal infection occurs it does not result in damage.
During the neonatal period:
 Congenital rubella may give rise to a number of manifestations which are self‐limiting
 The most frequent is thrombocytopenic purpura, which may manifest as a transient purpuric rash.
 Jaundice
 Bone lesions

10. Disease course and prognosis:
By the third day:
 The rash on the trunk has cleared
By the fourth day:
 The eruption on the limbs has also faded.
The rash may be absent in some 40% of cases.

11. Investigations:
 Labs must be carried out to confirm a diagnosis in pregnancy or immunosuppression.
 Serology remains the gold standard method.
 First clotted blood to be taken immediately upon the appearance of the rash as the antirubella
antibodies can be detected from the time when the rash appears.
 A second blood sample is taken after 7–10 days.
 IgM antibodies suggest acute or recent rubella infection.
 IgG antibodies appear 2–3 weeks later or may indicate prior exposure and immunity.
 In neonates, the presence of IgM and continued antibody production are
indicative of congenital infection.
 RT‐PCR amplification of viral RNA from saliva and throat swabs can also be done.
 Complete Blood Count:
 Normal or
 Leukopenia with an inconstant increase in Plasma Cells.

12. Management
Prophylaxis:
 Active immunization: with live attenuated rubella virus as part of MMR vaccine is offered to
infants aged 1–2 years old,
 A preschool booster of MMR is also recommended.
 At risk women for e.g. Medical or nursing staff and school teachers can also be given the
rubella vaccine.
 A quadruple vaccine including varicella is also available but there has been concern, but not
confirmation, that this combination leads to a slight increase in convulsions.
 Pregnancy is a contraindication to vaccine and should be avoided for 4 weeks after its
administration.
 Arthralgia is common in adult women 2–4 weeks after vaccination and in children a rubelliform
rash may occur.
 Encephalitis has been reported
Treatment:
 No specific treatment is needed.

13. Prodrome:
1-5 days
Forscheimer Spot:
Either in the prodrome
or the first day of rash
Day 1:
Rash Appears Day 2:
Day 3:
Rash on trunk clearedIncubation Period:
10-14 days
Lymphadenopathy:
5-7 days before rash appears
Face begins to
clear. Macules
on trunk begin to
coalesce. Limbs
show discrete
macules
Day 4:
Rash on
limbs
cleared
Rubella Timeline:

14. Topic to be Discussed in Future:
Erythema Infectiosum.
Previously Discussed:
Measles
Roseola Infantum