Thank you for your query on Healthcare Magic.
Up loading picture of this skin rash
is more useful in diagnosing the skin condition.
It may be an allergic one.
Look for any change in his diet, soap, or drinks.
If any thing is suspected from your observation, you can avoid it.
You can give that syrup in prescribed dose.
If the rash is itching, you can apply calamine
lotion externally over the rash.
Observe for his general condition.
Consult the doctor for physical examination and specific treatment.
Hope I have answered your query.