Skin prick testing
SKIN
SPT was performed using a single‐head metal lancet, a positive control (10 mg/mL histamine dihydrochloride), a negative control (50% glycerol and 50% buffered saline), egg white (EW) extract (ALK Abello) and fresh foods, including raw egg and BE (the latter using slurry made up of 1 g of the challenge food in 10 mL of saline). Skin weal diameter was recorded in milimeters after 15 min. The size of the wheal was determined as the arithmetic average of two perpendicular diameters including the longest one. The positive control test needed to be ≥3 mm, and the negative control test needed to be 0 mm. If the saline negative control test was ≥1 mm or the histamine positive control was ≤3 mm, SPT was considered inconclusive.