G.B.
It is an allergic reaction.
The body will increase and thicken phlem when it is ingesting something it is allergic to. Then, the thick phlem and secretions stick in the sinus and ear cavities, and that is the perfect grounds for fungus to grow.
Milk products, sugar, grains, (and processed food) GMO's... can all cause it.
Do an elimination diet. When I stopped eating sugar, soda, and fast foods my boogers totally disappeared. Boogers are a response to an inflammatory condition. ANY boogers, and thick phlem are NOT normal.
Eating LOTS of *organic* fruit and raw salads, real organic oatmeal (not boxed) apples, carrot juices, etc...helped my daughter tremendously.