Skin Prick Test
In an attempt to assess IgE binding in vivo , peanut-allergic subjects and non-allergic healthy controls were skin prick tested (SPT) with a panel of protein extracts created from raw, roasted and autoclaved peanuts and the resulting wheal diameters were measured (Table 1). Within the peanut-allergic group, a statistically significant reduction in mean wheal diameter was observed using the autoclaved extract when compared to raw (p < 0.05).
Additional information was revealed when the allergic group was further stratified into two groups: one group of patients who have previously experienced anaphylaxis to peanut or have demonstrated high likelihood of it based on past clinical tests, and the second group of patients known to experience only oral symptoms upon peanut consumption. A striking decrease in wheal size was observed when using autoclaved extracts compared to raw in the group that experiences oral symptoms. In contrast, this was not observed in the case of the group at risk for anaphylaxis. The roasted peanut extract showed a slight decrease in wheal size in the group at risk for anaphylaxis and an increase in the group of patients who experience oral symptoms.