MILK HYPERSENSITIVITY - KEY TO POORLY DEFINED GASTROINTESTINAL SYMPTOMS IN ADULTS

Lactose intolerance is a common adverse reaction to milk in adults, wh ile milk hypersensitivity is a disorder of infancy. We hypothesized th at milk hypersensitivity may cause many unspecific gastrointestinal di sorders in adults. Twenty adults were subjected to double-blind, place bo-controlled milk challenge. Phagocyte activity, and Fc(gamma) and co mplement receptor expression of phagocytes were assayed, and serum tot al IgE, milk-specific IgE, and serum reactivity to milk protein were d etermined. The challenge increased phagocyte activity and complement r eceptor expression of phagocytes in subjects designated milk-hypersens itive, who had gastrointestinal symptoms from milk ingestion but norma l lactose tolerance. The increase was not detected in lactose-intolera nt or control subjects. The milk-hypersensitive group was also disting uished from the lactose-intolerant group by enhanced serum reactivity to milk protein. Only two out of nine milk-hypersensitive subjects had detectable milk-specific serum IgE. It is concluded that milk hyperse nsitivity in adults, occurring as gastrointestinal reactions, may be m ore common than previously thought.