Amblyomma americanum mammalian meat and meat products. The allergy manifests as anaphylaxis — a life-threatening allergic reaction characterized by constriction of airways and a drop in blood pressure. This response is triggered by an IgE antibody to the mammalian oligosaccharide galactose-alpha-1,3-galactose (alpha-gal). As well as occurring in non-primate mammals, alpha-gal is also found in cat dander and in the drug cetuximab. Allergic reactions to alpha-gal usually occur 3–6 hours after consuming red meat, unlike allergic reactions to other foods, whose onset following consumption is more or less immediate, making it more difficult to identify what caused the reaction. Skin tests with standard
Allergic contact dermatitis to the level at which the toxin induces the up-regulation of the required mandatory cytokines and chemokines. It has also been proposed that the vehicle in which the allergen reaches the skin could take some responsibility in the sensitisation of the epidermis by both assisting the percutaneous penetration and causing some form of trauma and mobilization of cytokines itself. Once an individual is sensitized to an allergen, future contacts with the allergen can trigger a reaction, commonly known as a memory response, in the original site of sensitization. So for example if a person has an allergic contact dermatitis on