The first oral food challenge to barley
We examined the factors that influenced the results of all barley-OFCs
conducted between August 2012 and November 2020 in patients with a
history of wheat allergy. An open OFC to cooked barley (6.2% of
protein, based on standards tables of food composition in Japan 2015)
was performed according to the Japanese guidelines1for patients with a wheat allergy diagnosed by wheat-OFCs; they
completely avoided wheat or ingested some amount of wheat products as
OIT at the time of barley-OFC. The patients were instructed to ingest
18.6, 62, 186, 620, and 1,860 mg barley protein of cooked barley with
30-minutes intervals until obvious allergic symptoms were observed. Some
patients underwent barley-OFC with a different protocol, where they
ingested a total amount of at least 236 mg of barley protein. All
patients who had negative barley-OFC results were instructed to consume
at least 1,860 mg of barley protein at home to confirm that no allergic
symptoms were induced.