An Allergy Mango Test helps to determine whether an individual is allergic to mangoes or not. It is performed to measure the amount of IgE in the blood. Immunoglobulin E (IgE) is an antibody produced by the immune system. Antibodies are proteins that attack antigens, a foreign protein, such as bacteria, viruses, and allergens to help safeguard the body against the intruder. Mango contains urushiol, an oil found within the cashew plant family. When contacted, this oil can cause serious and sometimes life-threatening allergic reactions. Although rare, mango allergies may cause a cough, contact dermatitis, swelling of lips and tingling sensation on the tongue.