As you say yourself, it is very difficult to diagnose a rash without being able to see your son. This rash is definitely not due to the roseola. It sounds like a condition called molluscum which is a viral infection of the skin which is very resistant to treatment and is infectious to others.Please read more about molluscum on Google.
The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical exmanication, diagnosis and formal
advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.