Diagnosis of food<unk> es, including<unk> , begins with a medical history and physical examination. National Institute of<unk>  and Infectious Diseases (NIAID) guidelines recommend that parent and patient reports of food<unk>  be confirmed by a doctor because "multiple studies demonstrate 50% to 90% of presumed food<unk> es are not<unk> es." Skin prick testing Skin prick tests can be used to confirm specific food<unk> es. Skin prick tests are designed to identify specific IgE bound to cutaneous mast cells. During the test, a glycerinated<unk> n extract drop is placed on the patient's skin. The patient's skin is then pricked through the drop. This procedure is repeated with two controls: a histamine drop designed to elicit an<unk> c response, and a saline drop designed to elicit no<unk> c response. The wheal that develops from the glycerinated extract drop is compared against the saline control. A positive<unk> c test is one in which the extract wheal is 3mm larger than the saline wheal. A positive skin prick test is about 50% accurate, so a positive skin prick test alone is not diagnostic of food<unk> es. Oral food challenge The "gold standard" of diagnostic tests is a double-blind placebo-controlled oral food challenge. At least two weeks prior to an oral food challenge, the person is placed on an elimination diet where the suspected<unk> n is avoided. During the oral food challenge, they are administered a full age-appropriate serving of a suspected<unk> n in escalating size increments. They are continuously monitored for<unk> c reaction during the test, and the challenge is stopped and treatment administered at the first objective sign of<unk> c reaction. Oral food challenges pose risks. In a study of 584 oral food challenges administered to 382 patients, 48% (253) of challenges resulted in<unk> c reactions. 28% (72) of these challenges resulted in "severe" reactions, which were defined by the study as a patient having: lower respiratory symptoms; cardiovascular symptoms; or any four other, more minor, symptoms. Double-blind placebo-controlled oral food challenges are also time-consuming and require close medical supervision. Because of these drawbacks to the double-blind placebo-controlled oral food challenge, open food challenges are the most commonly used form of food challenge. Open food challenges are those in which a patient is fed an age-appropriate serving of a suspected food<unk> n in its natural form. The observation of objective symptoms resulting from ingestion of the food, such as vomiting or wheezing, is considered diagnostic of food<unk>  if the symptoms correlate with findings from the patient's medical history and laboratory testing such as the skin prick test.
Peanut allergy
Tree nut allergy
Corn allergy
Fruit allergy
Sesame allergy
Rice allergy
Shellfish allergy
Insect sting allergy