Usually fluid in the middle ear is caused by recurrent infections unusually upper respiratory infections, which causes nasal blockages or sneezing or runny nose and if you have chronic sinusitis also you can have middle ear effusion. This also causes dizziness because the pressure inside the ear increases and because the balance organ is just deep to it, it can cause imbalance. Usually removal of the fluid or correction of the fluid collection can create dizziness. So it is just decongestant locally or in the form of tablets or anti allergic medications or steam inhalations which help in removing the fluid in the ear and that corrects the dizziness.