Exanthema subitum is caused by -

Ans is 'a' i.e., HHV Roseola infantum (exanthem subitum)o Human herpesvirus 6 (HHV-6) virus causes roseola infantum, the most common exanthematic fever in children under the age of 2 years, with a peak incidence between 6 and 9 months,o The incubation period is 10-15 days.Clinical featureso Fever, ranging between 39.5 and 40o c., irritability, inflamed tympanic membranes and, occasionally, periorbital edema and haematuria are early manifestations,o Discrete rose-pink maculopapules develops on the neck and trunk,o Cervical and occipital lymph nodes are usually enlargedComplications:- Febrile convulsions, fatal hepatitis, and haemophagocytic syndromediagnosis by:- demonstrating seroconversion or rise in antibody titer to hhv-6, typically by indirect immunofluorescence.