My baby is allergic to everything, WHY?

My 19 moth old son, has always been very sick when it comes to having a cold, cough or just a plain runny nose. He started to have skin problems at around when he was about 5 mos. and shortly after he had full blown bleeding-eczema. He was getting staff infections from his open eczema patches. He is also a small baby and gets stomach bugs all the time. i always felt that he was a wheezier but the doctors reured me he was okay just a little congested. Around 9 mos. he was having sporadic allergic break out from Random things. Now he has trouble speaking because he cant hear that well because he has fluid in his inner ear. After a resent allergy test he was found to be allergic to everything. I am devastated and hopeless and so frustrated and worried. my husband is away to Afghanistan for a whole year and i also have a 3 year old who is as healthy as an OX. I have spent the last year and a half in the hospital/ doctors offices for breathing problems, sever staff infections, eczema, stomach bugs, yaou name it. Yet, with no resolution to his problems or any reason for why! I have done so much and dont know if there is anymore i can do, but i pray that someone knows what to do or anything that will help.