Please bring your kid to see Ear, Nose & Throat (ENT) specialist ASAP. I personally ever had 中耳炎 before and ended up having very serious consequences, cos' my infection almost went up to the brain and also affected my facial nerve. So, it can be really serious!
I went to an ENT doctor in Tsim Sha Tsui, his name is Dr. Wong Ngar Shun, Victor (but quite expensive)
I just know that my baby has Otitis Media this morning, doctor gave him antibiotics, need to take at least 7-day no matter recover or not. At first, nothing wrong but earache, now (half-day later) he has fever too...
Don't know how he got this, maybe from the kindergarten I guess. :-(