Comparison of tests to support the diagnosis of specific food allergies
To further evaluate the different diagnostic tests, we compared them against each other for each food. Table 4 shows the statistically significant comparisons of tests by food. For the diagnosis of peanut allergy, the SPT to peanut has a higher relative sensitivity and relative specificity compared to the sIgE. Ara h 2 shows a higher relative specificity compared to sIgE to peanut. When different techniques are used to measure CRD, Ara h 2 by ImmunoCAP has a higher relative specificity than Ara h 2 using ISAC. The relative sensitivity of Ara h 2 is higher than for BAT.
For the diagnosis of cooked HE allergy, sIgE has a higher relative sensitivity that SPT to egg white, SPP to raw egg white and ovomucoid. Ovomucoid performed better than ovalbumin. For CM allergy diagnosis, SPP to fresh CM had higher relative sensitivity and specificity than SPT using commercial extracts and higher sensitivity than sIgE to CM. sIgE to Casein performed better than SPT to CM. For the diagnosis of hazelnut allergy, sIgE and SPT show higher relative sensitivity than Cor a 14 and can help in ruling out allergy to hazelnut. Cor a 14 has a higher specificity than Cor a 9 and can used to rule in allergic disease. sIgE to wheat and shrimp respectively had a higher sensitivity and so will be more useful to rule out allergy while w-5 gliadin and Pen m 1 had higher relative specificity and could be used to rule in wheat and shrimp allergy respectively.