Testing total IgG, or more specifically IgG4 and IgG1 is one of the best ways of testing intolerance's. When testing for IgG4, it shows us a limited amount of false-positives giving us the most accurate results. The most commonly tested groups out of the four subgroups are IgG1 and IgG4. IgG1 and IgG4 are produced in a response to antigens which easily allows us to identify the intolerance.
Since the IgG1 antibodies are what show up first, we can find new food antigens by joining them with forming complexes. The immune system cells(macrophages) then destroy these complexes.
The IgG1 antibodies can then activate further immune reactions.
By comparison, an intolerance is not as severe and immediate as an allergy. These symptoms come on gradually; anything from 30 minutes up to a 48 hours later. Symptoms such as headaches, bloating, localized itching or skin irritations such as eczema, excessive mucous production, excessive gas, diarrhea, and fatigue.