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.