Little Wei Zhi had high fever and measles

This few days,little Wei Zhi fell sick.First it started with high fever on Thurs morning.The nanny called us to bring him for doctor consultation.It's terrible, the temperature went up to 39.6C and doctor immediately insert half tablet of fever medicine to the back side.Poor little Wei Zhi cried out loudly.Luckily the fever gone after that.
However,starting from Sat morning, we found red spots on Wei Zhi's face. We brought him to specialist again and according to doctor it might not be the real measles.There was no medicine given and the only advice is to drink more water.I am getting a bit worried about Wei Zhi who's weight did not gain since 6 months old and maintained at around 8kg till now at the age of 8 months.

After checking the growth percentile calculator, little Wei Zhi falls into the following percentiles: Weight = between percentile 10 and 25

http://www.loveyourbaby.com/baby-growth-calculator.html

What do the percentiles mean?
If the child is in the 20th percentile for weight, for example, he weighs more than 20 percent of children his age and less than the other 80 percent.

This means that Wei Zhi is under weight at the moment.