Hello! I just realize that my son has rashes on his feet and hands and body. I'm suspecting is HFMD. But there isn't any fever or blister looking rashes. Neither does he have ulcers. Is there any other symptoms?

Fever and ulcer - wait for those signs. Anyway hfmd is a viral disease, cannot take antibiotic. So suspect early also no use. Just make sure to quarantine him at home so don't spread to others. If he got fever, give Panadol. For the rash use calamine lotion.