A double-blind study for the diagnosis of cows' milk allergy

As a preliminary to investigating the mechanism by which cows' milk might provoke rhinitis a double-blind study was set up to identify a group of milk sensitive patients. Twenty-three patients with histories suggestive of sensitivity to dairy products, and whose symptoms had previously improved with milk avoidance yet recurred following milk challenge, entered the trial. During a six-day period the patients were twice challenged on a double-blind basis with 100 ml cows' milk. Twenty-one patients completed the study. Eight patients reacted to neither challenge, seven patients reacted to only one challenge, and six responded to both challenges. Only two of these six reacted identically to both challenges, and were considered to be milk allergic. It was concluded that cows' milk allergy of the immediate hypersensitivity IgE mediated form is rare.