hey there!
The dr is continually mentioning aspergillus with this elevated IgE probably because they tend to go hand in hand in cfers. It basically means that Jacob might have aspergillus growing in the lungs and is allergic to it. Like I said, this is a common condition in CFers known as Allergic Broncopulmonary Aspergillosis (ABPA). I myself have never experienced allergic reactions to aspergillus (I've had PLENTY of allergy related pulmonary issues at the same time of having aspergillus in my lungs though), but from what I've heard from people I've met and my own docs, it's relatively easy to treat-just a big pain in the butt. Chances are, Jacob will have to go on steroids for the allergy and abx (itraconazole is usually the drug of choice for combating aspergillus) for the infection.
You keep mentioning that his dr keeps saying that a high IgE INDICATES aspergillus-has Jacob had a sputum culture done to prove he indeed has aspergillus in his lungs? Is the doc not doing one and just assuming? I've had several occasions where my IgE levels were sky high and after a culture was done, I had no aspergillus but more allergy tests showed very reactive airways to dust and pollen around my house. Make sure you talk to the doc about a sputum culture. Steroids and extra albuterol-type (xopenez, flovent, advair) meds helped to get me through the season change.
As for the aspergillus, it is a fungus/type of mold. CFers can get it from anywhere. It is a frequent inhabitant of showers and bathrooms(where it's warm and moist) and soil (where it's warm, moist, and dirty, lol). Hope all goes well at the doc! The end result for Jacob will probably be steroids and antibiotics and, if further testing shows more, allergy pills or antihistamines. Just make sure he gets a culture done and the dr is not basing his lung bugs solely on IgE levels (I can't say that enough).
Hope he starts feeling better!!