derm

Question 1

A 10-month-old infant is brought to accident and emergency with a 3 day history of fever and a new onset rash affecting the arms, legs and abdomen that began today. Despite this fever the child has been his usual self and does not seem to be irritated by the rash.

On closer inspection, the rash appears erythematous with small bumps that are merging together. None of the lesions have scabbed over. The rash is predominantly on the limbs and there are no signs of excoriation. The child is now afebrile at 36.9ºC.

Bearing in mind the likely diagnosis, what is the most likely causative organism?

Answer 1

Roseola infantum is caused by human herpes virus 6

Question 2

Roseola infantum (also known as exanthem subitum, occasionally sixth disease) is a common disease of infancy caused by the human herpes virus 6 (HHV6).

what are the features of this disease?

Answer 2

• high fever: lasting a few days, followed later by a
• maculopapular rash
• Nagayama spots: papular enanthem on the uvula and soft palate
• febrile convulsions occur in around 10-15%
• diarrhoea and cough are also commonly seen

Question 3

what are other possible consequences of HHV6 infection?

Answer 3

• aseptic meningitis
• hepatitis