Not Rosie Cheek, but is rashes

Mei Mei is having rashes all over her body since Monday morning. Ah Mah did bought her to visit doctor, and diagnose as allergy, give her 3 types of medicine, allergy, prevent itchy and colamine lotion. But did not told what causes the allergy. I've spend sometimes to search it from website, but there are too many types of rashes till I confuse which one it belong. I am guessing a few possibility:
1. Cause by wool (I place Mei Mei in the baby cot when I helping kakak to change quit cover)
2. Cause by flea (as hubby let her play in the garden, by only wearing a budy suit, without long pant. Neighour claims that there is a wild dog always come to our housing area which is very dirty and believe it have many fleas)
3. Cause by plain bun (I share with her during my breakfast time)
Today is the 4th day, the rashes spread here and there, red and is burning. She have taken allergy syrup since monday but it don't seems better. I try not to give her the itchy medicine, as I think is not necessary for a baby. As per sister in law, I may need to let her take allergy medicine for another 2 days, if persists, need to give another type of medicine. I pray that she can get well soon, please don't let her suffer for so long.