Allergists focus on traditional medical issues of acuity, life and death. IgG issues most often arise in the evaluation of chronic illness that often presents as refractory mental problems - like ADHD.
Let's face the naming thing squarely, head on. ADHD and ADD labels provide more confusion than understanding, more complexity than common sense. Why, because they describe symptoms that remain on the surface.
Prevalence missing: Using the same, outdated DSM-4 [Diagnostic Statistical Manual] criteria, with even more disturbing diagnostic limitations for ADHD recognition encouraged by DSM-5, the problem is global.
One of the many reasons so many deny ADHD as a biologically valid medical entity is the simple observation that too often the ADHD stimulant meds simply don't work predictably.