Final answer:
A person with a peanut allergy would typically have high levels of IgE antibodies specific to peanuts in their blood, and their condition may also be indicated by elevated histamine levels and increased eosinophil count.
Step-by-step explanation:
The blood test of a person suffering from a peanut allergy would reveal high IgE antibodies to peanuts. IgE antibodies are specifically associated with allergic reactions and anaphylaxis. When an allergic individual eats peanuts, the peanut-specific IgE present on the surface of mast cells triggers these cells to release histamine and other inflammatory chemicals, leading to the allergic symptoms. The presence of elevated levels of histamine and an increased eosinophil count may also be noticed, as these are part of the allergic response. However, it is important to note that the diagnosis of type I hypersensitivities like peanut allergy is complex and usually involves a well-documented patient history and other diagnostic tests in addition to serum IgE measurement.