A milk allergy is a food allergy, also called as dairy allergy is an adverse immune reaction to one or more of the protein constituents of milk from any animal (most commonly in cow's milk). The body manifests either an antibody-based immune response or a cell-based immune response to these allergens. Antibody responses are usually rapid and can involve anaphylaxis, a potentially life-threatening condition. Cell-mediated responses take hours to days to appear. The effects of antibody-mediated allergy are rapid in onset, evolving within minutes or seconds. These allergies always arise within an hour of drinking milk; but can occasionally be delayed longer when eating food containing milk as an ingredient. The effects of non-antibody-mediated allergy is delayed; because it is not caused by antibodies, it can take several hours, or even up to 72 hours to produce a clinical effect. The most common symptoms for both types are hives and swelling, vomiting, and wheezing, with symptoms first arising in skin, then the GI tract, and less commonly, the respiratory tract.