Thank you for your query.
If the rash
, which has erupted all over the body, is pustular then your son needs to be examined and treated accordingly. Pustular lesions mean an infection for which a systemic antibiotic may be required.
Application of steriods on molluscum
should be avoided as it can aggravate the viral infection.
It is very difficult for me to give you a guidance without a look at the lesions. Hence, my advise would be to consult your doctor or a dermatologist
and follow their advice.
I hope I have answered your query to your satisfaction.
Wishing an early relief to your son.