D2.287 - Clinical characterization and predictors of diagnosis and severity in sunflower seed allergy in a pediatric population

The diagnostic tools for sunflower seed (SFS) allergy are scarce, and its clinical significance lies in the potential to cause severe reactions. We aimed to evaluate the utility of allergy workup as predictors of diagnosis and reaction severity in pediatric patients that undergo SFS oral food challenge (OFC). 

We conducted a retrospective descriptive study encompassing all SFS OFCs performed between January 2018 and November 2025 at the pediatric hospital Niño Jesús, Spain. Demographic data, clinical history, positive Skin Prick Test (SPT)≥3mm, positive sIgE and molecular diagnosis (Jug r 1, Jug r 3, Ara h 2 and Ara h 9)>0.35kU/L and OFC reaction characteristics (threshold dose, severity according to oFASS5 and adrenaline requirement) were analyzed. ROC curve analyses were performed to assess the ability of diagnostic markers to predict moderate-to-severe reactions (oFASS5≥3).

Of 217 SFS OFCs, 17 (7.8%) were positive (group A). In group A (14 males; median age 11 years, [5-19]), 29% identified SFS as the implicated food in their index reaction, whereas 71% had previously reacted to other nuts/seeds. Diagnostic workup revealed that in group A, 12 patients (70.6%) had a positive SPT (mean wheal: 5.3mm) versus 115 (57.5%, mean wheal 3.4mm; p=0.002) in group B (negative OFC). Group A showed sensitization to 2S albumin in 4/14 patients (28.5%) and to LTP in 9/14 (64.3%) versus 58/128 (45.3%; p=0.269) and 70/128 (54.6%; p=0.579), respectively, in group B. Within group A, 9 patients (52.9%) showed positive sIgE levels (median: 4.8kU/L [0.6–39.2]) and the cumulative threshold dose exceeded 60 seeds (approximately 0.6g of protein) in 11 patients (64.7%). While 3 patients (17.6%) presented mild reactions (oFASS 1-2), 14 (82.4%) presented moderate-to-severe reactions (oFASS≥3). Adrenaline was administered in 6 patients (35.3%), with 1 patient requiring two doses. ROC analysis for severity prediction (moderate-severe reactions) yielded an Area Under the Curve of 0.68 for SPT, 0.60 for SFS sIgE, and 0.65 for the SFS sIgE/total IgE ratio.

In our cohort, the allergy workup showed that the SFS positive OFC group had a significantly larger SPT but had limited ability to predict reaction severity. Larger studies are needed to confirm these results.