Infectivity of chickenpox lasts for:

Ans. (b) 6 days after onset of rash "Period of communicability of varicella range from 1 to 2 days before the appreance of rash, and 4 to 5 days there after." The patient ceases to be infectious once the lesions have crusted. Scabs are not infective So, option "a" is wrong. Impoant features of chickenpox Causative agent - Varicella zoster virus (HHV type 3) Incubation period - 14 to 16 days Secondary attack rate - 90% Rash Chickenpox Smallpox Superfici Deep seated Pleomorphi Only one stage of rash at 1 time Centripet Centrifugal Unilocular Multilocular Dew drop like appearance Umbilicated Inflammation (+)nt No area of inflammation around vesicle Mostly flexor surface Mostly extensor surface