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Question 741
Obstetric infection → Viral
Classification
Question
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Infectious period before chickenpox rash
Question Stem
A pregnant woman has been in contact with a person who subsequently developed chickenpox. From when before appearance of the index case's rash is chickenpox considered infectious?
Options
A
6 hours
B
12 hours
C
24 hours
D
48 hours
E
72 hours
Explanation
Chickenpox is infectious for 24 hours before appearance of the rash and remains infectious while skin lesions are active. Infectivity ceases when the lesions have crusted over. The timing of contact relative to this infectious period is therefore part of determining whether an exposure is significant.
Option Validity
A) the infectious period begins earlier than 6 hours before the rash.
B) 12 hours is shorter than the interval specified in the guideline.
D) the guideline specifies 24 hours rather than 48 hours before rash onset.
E) 72 hours is not the stated pre-rash infectious interval.
Further Reading
RCOG Green-top Guideline No. 13, Chickenpox in Pregnancy, section 4.3.