There were statistically significant differences in SPT, peanut-sIgE, peanut Ara h2-sIgE component and CD63+ LAD2 cells activation between the 4 groups at both 36m and 7-11y (p<0.001) – Figure 1, Figure 2, Figure 3 and Figure 4. Over time, children with persistent PA had SPT and peanut-sIgE and Ara h 2-sIgE levels that were suggestive of PA as early as 12m of age that increased and remained persistently high; however, MAT was highest at the 36m time point. New PA children showed increasing SPT, peanut-sIgE and Ara h 2-sIgE over time but the levels increased slower over time compared to those with persistent PA. The MAT in this group also remained low at all time points. The new PA children also had an increase of Ara h8-sIgE from 36m to 7-11y although this was not significant. The time at which this increase occurred suggests that these children developed their PA at some point between 36m to 7-11y of age. Both children had peanut introduced early into their diet with reports of both consuming peanut at 12m. However, at 36m one was no longer consuming peanut but the other was and at 7-11y, both were no longer consuming peanut and their biomarkers were consistent with PA. The child who outgrew PA had raised SPT and peanut-sIgE levels at 12m of age which was consistent with PA diagnosis. However, by 36m, although SPT was still high, their peanut-sIgE levels had already started to decrease and by 7-11y both SPT and peanut-sIgE were low. In this child, MAT remained low at all time points. Children who were NA had consistently low biomarkers across time in keeping with what would be expected of non-allergic children. There were significant differences in SPT between the groups at the 12m, 36m and 7-11y time points and total sIgE at the 36m and 7-11y time points. Specifically, Ara h 2-sIgE was already significantly higher (p<0.001) in persistent PA group at 12m of age (9.3kUA/L) and increased to 19.8kUA/L by 7-11y of age. This differs to the new PA group who at 12m had undetectable Ara h 2-sIgE (0.03kUA/L) that then increased by 7-11y (6.4kUA/L) which is when they were diagnosed with PA. MAT was significantly different between the groups with higher mast cell activation occurring in persistent PA group at the 36m and 7-11y time points.