Contact urticaria to cow milk.

A patient with contact urticaria to cow milk is presented. Contact sensitivity was documented to whole cow milk, skim milk, commercial condensed milk, and milk heated to 80 degrees C for 30 min. Contact sensitivity was also documented to casein and lactalbumin. Unlike a previous report our patient's sensitivity to heated milk precluded its use in the diet. Thus, heating milk does not necessarily reduce allergenicity to its component proteins.